EUGENE, Ore. – With water pounding on the track and the finish line in plain sight, 10,000-meter runner Galen Rupp waved to the crowd, smiled and stuck out his tongue.

Catching a bit of rain. And soon, he’ll be catching a plane to London.

Running in the pouring rain Friday, Rupp still set an Olympic trials record, finishing in 27 minutes, 25.33 seconds to qualify for his second Olympics.

His was the most impressive performance on the official opening day of the trials in rainy Eugene, save possibly for the effort decathlete Ashton Eaton put in. Eaton made it through the first five events on pace to break a 20-year-old American record held by Dan O’Brien.

While the long-distance runners and decathletes were grinding, the sprinters used Day 1 to warm up — not a bad idea considering the wet chill that gripped Hayward Field all day long.

Sanya Richards-Ross, LaShawn Merritt, Allyson Felix, Dawn Harper and Carmelita Jeter all made it through their heats with minimal problems.

“Other than it messing up my hair, it’s OK,” Richards-Ross said after running her first 400-meter qualifier in 51.69 seconds.

Rupp will be joined on the men’s 10K team by Matt Tegenkamp (27:33.94) and Dathan Ritzenhein (27:36.09).

Ben True of North Yarmouth finished 12th in 28:08.17. He’ll have one more chance to make the Olympic team next week in the 5,000.

In the only other final held Friday, Amy Hastings won the women’s 10,000, edging Natosha Rogers (31:59.21) and Shalane Flanagan (31:59.69).

Flanagan will bypass the 10,000 at the Olympics in favor of the marathon, and Rogers does not have the Olympic “A” standard of 31:45.00. As a result, the other two spots on the U.S. team will go to fourth-place finisher Lisa Uhl (32:03.46) and seventh-place finisher Janet Bawcom (32:17.06).

Becky O’Brien of Cumberland didn’t advance to Sunday’s finals in the discus. She’s also scheduled to compete next week in the shot put.

Merritt, the defending Olympic champion at 400 meters, sidestepped a runner who fell in the lane next to him and finished in 45.36 seconds, the best time in the men’s heats.

“I saw him and I had to do a little step more toward the inside of my lane, where I should’ve been in the first place,” Merritt said.

The 400 runners have semifinals today, with finals scheduled for Sunday.

In the women’s 100, Felix and Jeter each won their heats easily.

“It was OK. Just wanted to make it safely to the next round,” Felix said. “I feel like tomorrow will be better. Always good to get that first one out of the way.”

In the women’s 100 hurdles, Harper, the defending Olympic champion, won her heat in 12.79 seconds — a victory she earned even though she didn’t have the ideal, track-grabbing spikes in her shoes.

“I actually change spikes” when it rains, she said. “Usually, the pointier ones grab the track. It was on my mind out there because I had the older ones in.”

Meet organizers scrubbed women’s pole vault preliminaries, meaning all 29 athletes, including 2008 Olympic silver medalist Jenn Suhr, will move to Sunday’s finals.

In the decathlon, Eaton was ahead of a world-record pace for two events. His shot put throw of 46 feet, 7¾ inches slowed him down, but he still led two-time world champion Trey Hardee by 205 points with six events to go.

Eaton, an Oregon native, looked very much at home in the steady rain. Everyone else was trying to make the best of it.

“You have to adapt to what the weather is, how the track is,” Merritt said. “Know what you’re doing before you get out there. You know the weather, the wind, and the track is slippery. It’s all about going in with a plan and executing.”