QUALIFICATION: First two in each heat, plus the next two fastest times.
A first lap of 53.23 by leader Trinity Gray of the US was his attempt to strike terror into the heart of Russian Yuriy Borzakovskiy, who was in his customary rear position as the race reached its midpoint. As usual, it didn't work against the apparently dauntless young Russian.
With 300 left, the 19-year-old Borzakovskiy moved into overdrive and had solidly dispatched all except Gray by the bell.
The familiar kick came with 100 left. A glance right, a glance left, and then an easy stride into the finish brought Borzakovskiy the win in 1:47.28, as Gray held on for second (1:47.59) ahead of Ireland's Daniel Caulfield (1:47.83).
The runner with the top credentials in the heat, David Lelei of Kenya, moved up into the lead at the bell after spending a relaxing pair of laps in the middle of the field during the first half of the race.
Glody Dube of Botswana gave chase and moved into second, with Sweden's Abdirizak Dirshe following in third.
Coming into the final straight, Lelei and Dube had no problem finishing one-two in a relatively tepid 1:50.53 and 1:50.73, respectively.
But Dirshe couldn't fend off the finish of Elliott Gaskins of the US, who clipped the Swede for third, 1:51.04 to 1:51.28.
Milton Browne's lead in the early stages was short-lived, as South Africa's Johan Botha--the defending world champion--moved ahead of the Barbadian just before the 500-meter mark.
Holland's 20-year-old budding star, Bram Som, followed Botha past Browne, and this pair of runners easily controlled the final stages of the race, slowing almost to a walk at the end.
Botha clocked 1:49.77 while Som was timed in 1:49.84. Lukas Vydra of the Czech Republic joined in a futile chase, finishing third in 1:50.99.
To the cheers of the local fans, Portugal's Joao Pires took an ephemeral lead after 100 meters, only to lose it quickly to Spain's Roberto Parra.
But Pires came back in the second half of the race to take over the lead once again, just after the 400-metre mark.
That was the cue for Tom Omey of Belgium to add his touch to the tight race, as he moved into the lead heading into the final turn.
Benjamin Kipkurui looked to be in good position to make a run at the leaders at the end, but he faded badly as Parra came back strongly at the end, pipping Pires at the end for second, 1:50.12 to 1:50.13, and almost nipping the front-running Omey (1:49.83) at the finish line.
Andre Bucher of Switzerland took a no-nonsense approach to his heat and went to the lead right from the gun. And there he hoped to stay the rest of the way.
Somehow the script became altered.
Sergey Kozhevnikov of Russia held second behind the Swiss runner with 300 metres remaining, but at the bell, the Russian relinquished his position to France's Florent Lacasse.
As Bucher, Lacasse, and Kozhevnikov moved down the backstretch for the final time, Poland's Pawel Czapiewski decided to do his Borzakovskiy imitation.
Starting just before the final turn, Czapiwski moved wide around the three leading runners, and then scored a thrilling win in a personal-best 1:47.75, as Lacasse (1:47.82) and Bucher (1:47.88) stayed close at the end.
Only two semifinal spots were awarded on time. They were claimed by Caulfield and Bucher.