All four American women advanced to the IAAF World Championships 100m hurdles final to be held tomorrow night in London.

The overwhelming favorite for gold -- U.S. champion Kendra Harrison -- generated some drama when she clipped the first hurdle and had to gut her way to the finish line in third. Her time of 12.86 would be fast enough to nab the final time qualifier.

"I didn't have the best start and I hit [the hurdle] with my lead leg," Harrison said after the race to Lewis Johnson. "I just tried not to panic and trusted everything would work out. When you hit a hurdle in a race, you gotta keep going like nothing happened."

London will mark Harrison's career debut in a global championship final. In 2015 she was disqualified from the semi-finals in Beijing, and in 2016 she placed sixth at the U.S. Olympic Trials and did not make the Olympic team, although she followed that disappointment by setting a world record of 12.20 and winning the Diamond League series.

USA's Dawn Harper Nelson, the 2008 Olympic champion, won Harrison's heat in 12.63. The 33-year-old did not qualify for the 2016 Olympic Games, but addressed track fans' expectations for another Team USA medal sweep in the event after the trio of Bri Rollins, Nia Ali, and Kristi Castlin did so in Rio.

"We're not gonna talk about the 's' word," Harper Nelson said. "We're tough ladies and we're just gonna execute."

2016 Olympic silver medalist Ali placed second in her heat behind 2012 Olympic champion Sally Pearson to automatically advance, while Christina Manning convincingly won her heat to advance to her first world final.

Women's 100m Hurdles finalists:

RANK	ATHLETE	COUNTRY	MARK
1	Sally Pearson	Australia	12.53Q
2	Dawn Harper Nelson	USA	12.63Q
3	Christina Manning	USA	12.71Q
4	Pamela Dutkiewicz	Germany	12.71Q
5	Nia Ali	USA	12.79Q
6	Nadine Visser	Netherlands	12.83q
7	Alina Talay	Belarus	12.85Q
8	Kendra Harrison	USA	12.86q