Omaha, NE (My Sportsbook) - The oldest active U.S. swimming Olympic gold medalist took the first step toward clinching a spot in her unprecedented fifth Summer Games on Thursday.

Dara Torres advanced to the semifinals of the 100-meter freestyle with the third-best time in the preliminary heats at the Olympic trials.

The 41-year-old Torres, now a mother of a two-year-old daughter, finished with a time of 54.57 seconds, behind Natalie Coughlin and Lacey Nymeyer. Coughlin's time of 53.64 seconds set a trials record.

It's been an incredible Olympic run for Torres, winner of nine medals, starting with a relay gold in 1984 in her current home city of Los Angeles, and most recently capturing four medals in 2000 -- this after coming out of a seven-year retirement.

"I wasn't expecting to be that nervous," said Torres, who is trying to make the Olympics for the first time since 2000. "I felt like I was in my first Olympic trials."

Even if Torres doesn't have a qualifying time tonight in the semifinals, she can still fall back on the 50-meter freestyle, the other event she has entered at the trials. Those preliminary heats take place Saturday.

Torres currently holds the American record in the 50-meter freestyle, which she set last August, just 15 months after giving birth to her first child.

Katie Hoff, who is less than half Torres' age at 19, made it to tonight's semifinals with the eighth-fastest time of 54.95. Hoff has already won four finals at these trials, including two on Wednesday.

Thursday's day session also brought preliminary heats for the men's 200-meter backstroke and 200-meter individual medley, while the women had heats in the 200-meter breaststroke.

Ryan Lochte had the top time in the heats for the IM at 1 minute, 59.49 seconds, just .21 seconds ahead of world record-holder Michael Phelps.

"At this point it is just adrenaline," said Phelps, who captured the final of the 200-meter butterfly on Wednesday. "It does not matter how tired you are."

Rebecca Soni had the best time in the heats for the women's 200-meter breaststroke at 2 minutes, 24.65 seconds, just in front of Keri Hehn. Amanda Beard, trying to make her fourth Olympic team, qualified for tonight's semifinals by finishing third.

Aaron Peirsol qualified for the semifinals of the 200-meter backstroke with a best time of 1 minute, 57.05 seconds, barely ahead of Nick Thoman. Tyler Clary and Lochte had the next two best times.