Even before events took a dramatic turn in the men’s 100 metres, the Jeremy Wariner – LaShawn Merritt clash over the full lap was billed as the showdown of the Games. And both look extremely well prepared after their convincing and dominating victories in the semi-finals tonight.

In the first of three semis, defending Olympic and two-time World champion Wariner wasted little time to stamp his authority. On fire out of the blocks, the 24-year-old Texan made up the stagger on the field by midway, and once through the turn, gradually shut it down, looking to his outside some 40 metres from the finish before cruising through the line in 44.15. This season, only he and Merritt have run faster.

And Merritt was even faster tonight. Out quickly but more patiently than Wariner, the 22-year-old U.S. champion gradually built a comfortable lead with what appeared to be a very evenly run race. He was unchallenged over the final 100 metres, stopping the clock in 44.12.

“I’m excited for the finals,” said Wariner, who leads the world this year at 43.86. “I knew where I was at. I did everything I wanted to.”

Said Merritt, who’s run 44.00 this year: “Anything can happen on any day. I’m in the best shape of my life. I’m ready to show the world what I can do.”

In 2008, the two have split their four meetings. The lane draw may be critical; both of Wariner’s victories came when Merritt ran to his outside. In Thursday’s final, Merritt will line up in lane four, and Wariner in seven.

Behind him, Briton Martyn Rooney improved yet again, making up two spots over the final 50 metres to finish second in a personal best 44.60, just ahead of Swedish record holder Johan Wissman, who advanced easily on time. Renny Quow of Trinidad, moved on as well after his 44.82, also a career best.

“The last 100 metres were hard,” said Rooney, who as each race passes, looks more and more a medal contender. “I had to run a personal best to get through.”

Meanwhile, Bahamian Chris Brown, this season’s third fastest, was the only other runner remotely close to Wariner and advanced easily with his runner-up finish in 44.59. Although they failed to advance from Heat 1, Belgian Kevin Borlee (44.88) in third, Costa Rica’s Nery Brenes (44.94) in fourth and Tabarie Henry (45.19) from the U.S. Virgin Islands in seventh each produced national records.

Godday James of Nigeria took the early lead in heat 2, followed by Frenchman Leslie Djhone and Australian champion Joel Milburn. But as James began to fade heading off the final bend, it was U.S. indoor champion David Neville who began his surge towards the finish. As Milburn slowed, Neville gained but neither would catch Djhone who won with a season’s best 44.79. Neville stopped the clock in 44.91 to take move on as well.

Bob Ramsak for the IAAF