Felix Sanchez of Dominican Republic celebrates after winning the gold medal in the Men's 400m Hurdles final on Day 10 of the London 2012 Olympic Games on 6 August 2012 (Getty Images) © Copyright
But as surprising as most of tonight's finals were, the most shocking was the return to form of Felix Sanchez in the 400m Hurdles. His Olympic victory eight years ago in Athens was his last major victory, marking the end of his dominance that had spanned several seasons.
Despite having not broken 48 seconds since then, he had always remained competitive at major championships. But few would have expected him to tear apart the form book and upset his younger rivals.
His semi-final run yesterday of 47.76 provided a glimpse of what was to come, and he followed it up in today's final with a 47.63 victory – the exact same time he ran to win Olympic gold in 2004. At 34 – the oldest in tonight's final – he becomes the oldest ever medallist and champion in the event at the Olympic Games.
US Champion Michael Tinsley rose to the occasion on his major championships debut, setting a PB of 47.91 for silver as Culson was third (48.10), one place ahead of World champion Dai Greene (48.24). Defending champion Angelo Taylor – who, like Sanchez, has also won Olympic titles eight years apart – was fifth in 48.25.
At the other end of the age spectrum, 19-year-old Kirani James became the second-youngest winner of an Olympic 400m title, running away from the field in the closing stages to win by more than half a second in a final that was devoid of American sprinters.
His winning time of 43.94 was a huge personal best and makes him the first non-American to break 44 seconds. He was followed across the line by another 19-year-old, World Junior champion Luguelin Santos, who ran 44.46 to take silver – the second medal of the night for the Dominican Republic, following Sanchez's victory in the 400m Hurdles.
Trinidad & Tobago's Lalonde Gordon improved on the PB he set in the heats with 44.52 for bronze. But it was difficult not to feel sorry for Chris Brown of the Bahamas. After finishing fourth at the 2005 World Championships, the 2006 Commonwealth Games, 2007 World Championships and 2008 Olympics, the 33-year-old once again missed out on a medal by one place.
Adams and Isinbayeva surrender Olympic titles
Shot putter Valerie Adams was another defending Olympic champion to be beaten tonight. Although Nadezhda Ostapchuk entered the competition as the world leader, most of her top throws were achieved at home in Belarus and Adams often had the upper hand at major championships.
But tonight Ostapchuk was unstoppable as four of her five valid marks would have easily been enough to take gold. She went out to 21.31m in round two and extended her lead in the next round with 21.36m – the best mark at the Olympics since 1988. Adams opened with 20.61m and improved to 20.70m in round three, but that remained her best mark of the competition.
Russia's Yevgeniya Kolodko pulled a PB out of the bag with her last throw to move from fifth to bronze with 20.48m. With four women over 20 metres, nine over 19 metres and a winning mark of 21.36m, this was the highest-quality Olympic final for 24 years.
Yelena Isinbayeva was the first woman to win back-to-back Olympic titles in the Pole Vault and tonight she was looking to extend her record with a third gold. But on an evening where cold and breezy conditions wreaked havoc with the vaulting runway, the Russian superstar had to settle for bronze.
More than half of the 12 finalists had exited the competition without clearing 4.55m. Five women were left as the bar moved to 4.70m – the height at which German duo Martina Strutz and Silke Spiegelburg bowed out.
It left just Jenn Suhr, Yarisley Silva and Isinbayeva to fight it out for the medals. Suhr, the American record-holder, recorded her first failure of the competition at 4.75m, but her second-time clearance meant she maintained her lead.
Silva equalled her own Cuban record with that height, while Isinbayeva failed twice at it before saving her final attempt for the next height, 4.80m.
None of the medallists cleared that final height, which meant the positions remained the same as Suhr went one better than the silver medal she won in Beijing four years ago.
While Russia missed out on gold in the Pole Vault, Yuliya Zaripova made up for it in the 3000m Steeplechase. The World champion lived up to her favourite tag with some textbook front-running to take gold with a personal best of 9:06.72.
The top two positions from Daegu last year were replicated as Tunisia's Habiba Ghribi once again took silver with a national record of 9:08.37. Ethiopian record-holder Sofia Assefa held off a late charge from African record-holder Milcah Chemos to take bronze in 9:09.84.
Favourites fall in 400m Hurdles semis
Since winning gold in Beijing four years ago, Melaine Walker has built up an incredible record at major championships, always producing her best form of the year and always with a sub-53 clocking. But tonight that came to an end as she finished a distant sixth in her semi-final.
Instead it was 2010 European Champion Nataliya Antyukh who stole the show, improving her own world-leading mark with a 53.33 win in the first semi-final with Zuzana Hejnova in second (53.62).
World champion Lashinda Demus looked very comfortable in taking the second semi in 54.08, while Nigeria's Ajoke Odumosu led from the outset to win the third semi in a national record of 54.40.
But Walker wasn't the only big contender to falter. Britain's Perri Shakes-Drayton – who scored an impressive victory at the London Diamond League – finished third in her semi with 55.19 with European Champion Irina Davydova two places down.
After an initial disqualification of Denisa Rosolova from the third race, it looked as though Shakes-Drayton would progress to the final, but the Czech athlete was later reinstated.
The women's 200m also got underway with all the big contenders getting through to the semi-finals. Newly-crowned Olympic 400m champion Sanya Richards-Ross was the fastest of the round with 22.48, while Allyson Felix ran a very easy 22.71. Shelly-Ann Fraser-Pryce and Carmelita Jeter – the top two in the 100m – also won their heats.
But two-time Olympic Champion Veronica Campbell-Brown was just third in her heat. There was certainly more in the bag for the Jamaican, but her position may affect her lane draw in the semi-finals.
Foster-Hylton out, Borzakovskiy scrapes through
After a couple of injury-hit seasons, 2009 World champion Brigitte Foster-Hylton made a superb return to form earlier this season in the 100m Hurdles. The 37-year-old could have been a medal contender here in London, but in this morning's heats she clipped a barrier and missed out on making the next round.
But the Jamaican was the only surprise in the first round of the event, as all the other medal hopes made it through to the semi-finals. World champion Sally Pearson impressed with her 12.57, which is the fastest ever recorded in the first round at the Olympics, although not the fastest ever quarter-final (which this round effectively was).
Two-time European champion Nevin Yanit beat Olympic champion Dawn Harper in their heat, 12.70 to 12.75. Lolo Jones and Kellie Wells were among the fastest with respective times of 12.68 and 12.69 to win their heats.
The men's 800m heats also got underway, despite a few minor controversies. World record-holder David Rudisha guaranteed his place in the semi-finals with a very easy looking 1:45.90, equalling the time of World Junior Champion Nijel Amos from the first heat.
Abubaker Kaki, Mohamed Aman and Nick Symmonds were among the other heat winners, but Algeria's Taoufik Makhloufi – who won his 1500m heat and semi-final in impressive fashion – pulled up in his heat after just 200m. He was disqualified from taking part in any other event at the Games for not giving a bona fide effort, but was later reinstated.
Poland's Marcin Lewandowski was just the sixth athlete to cross the line in his heat, but he was obstructed during the race by Mohammad Al-Azemi and was later allowed to progress to the semis.
Meanwhile, 2004 Olympic champion Yuriy Borzakovskiy finished just fifth in his heat, but scraped through to the next round as the slowest of the fastest losers.
In the women's 1500m heats, Genzebe Dibaba and Yekaterina Martynova – both sub-four runners this year – failed to make it to the semi-finals. Dibaba, the World Indoor champion, was taken off the track in a wheelchair, while Morocco's Btissam Lakhouad failed to finish.
But Ethiopian record-holder Abeba Aregawi looked good in winning her heat in 4:04.55, equalling the fastest ever heat time at the Olympics. Others to progress included Yekaterina Kostetskaya, Maryam Yusuf Jamal, European Champion Asli Cakir and World Champion Jenny Simpson.
There were fewer surprises in the qualifying of the men's Discus. Defending champion Gerd Kanter overcame two fouls to post the best mark of the day with 66.39m. Two-time World champion Robert Harting qualified with ease (66.22m) along with Virgilijus Alekna (63.88m) and Ehsan Hadadi (65.19m).
Jon Mulkeen for the IAAF
- Felix Sanchez of Dominican Republic celebrates after winning the gold medal in the Men's 400m Hurdles final on Day 10 of the London 2012 Olympic Games on 6 August 2012 (Getty Images) © Copyright
- A general view of the Women's 3000m Steeplechase final on Day 10 of the London 2012 Olympic Games at the Olympic Stadium on August 6, 2012 (Getty Images ) © Copyright
- Silver medalist Valerie Adams of New Zealand, gold medalist Nadzeya Ostapchuk of Belarus and bronze medalist Evgeniia Kolodko of Russia pose on the podium during the medal ceremony for the Women's Shot Put final on Day 10 of the London 2012 Olympic Games at the Olympic Stadium on August 6, 2012 (Getty Images) © Copyright
- Jennifer Suhr of the United States celebrates after winning the gold medal in the Women's Pole Vault final on Day 10 of the London 2012 Olympic Games on 6 August 2012 (Getty Images) © Copyright
- Kirani James of Grenada leads the field to win the Men's 400m final on Day 10 of the London 2012 Olympic Games at the Olympic Stadium on August 6, 2012 (Getty Images) © Copyright
- Jennifer Suhr of the United States competes in the Women's Pole Vault final on Day 10 of the London 2012 Olympic Games at the Olympic Stadium on August 6, 2012 (Getty Images) © Copyright
- Yuliya Zaripova of Russia celebrates as she crosses the finish line to win the gold medal in the Women's 3000m Steeplechase final on Day 10 of the London 2012 Olympic Games on 6 August 2012 (Getty Images) © Copyright
- Nadzeya Ostapchuk of Belarus celebrates after winning the gold medal in the Women's Shot Put final on Day 10 of the London 2012 Olympic Games at the Olympic Stadium on 6 August 2012 (Getty Images) © Copyright
- Kirani James of Grenada reacts after he crosses the finish line to win the gold medal in the Men's 400m final on Day 10 of the London 2012 Olympic Games on 6 August 2012 (Getty Images) © Copyright