Britain's Jessica Ennis competes in the 100-meter hurdles portion… (Jamie Squire / Getty Images )
LONDON — When Britain's Jessica Ennis set an Olympic heptathlon hurdles record Friday morning, she also set the pace for the opening day of track and field competition.
In the first event at a jampacked Olympic Stadium, she ran the 100-meter hurdles in 12.54 seconds, breaking the Olympic heptathlon hurdles record set by Jackie Joyner-Kersee in 1988. In Friday's finale Tirunesh Dibaba of Ethiopia defended her 10,000-meter Olympic title in a world-leading time of 30 minutes 20.75 seconds, followed by Kenyans Sally Kipyego (30:26.37) and Vivian Cheruiyot (30:30.44) in personal-best times.
Thirteen of the top 14 finishers in the 10,000 ran national-, personal- or season-best times. Americans Amy Hastings at 31:10.69, Janet Cherobon-Bawcom at 31:12.68 and Lisa Uhl at 31:12.80 hit personal bests while finishing 11th, 12th and 13th.
PHOTOS: London Olympics, Day 7
In distances short and long, with hurdles to conquer or nothing between them and the finish line but raindrops, athletes covered ground in astonishingly fast times Friday. "It felt nice," Cheruiyot said of conditions in the stadium. "The wind was very quiet. I enjoyed it."
Besides Ennis, who led the heptathlon through four events, the most eye-opening performance was by Carmelita Jeter of Gardena, whose blazing 10.83 in the first round of the 100 was the fourth-best time in the world this season. Blessing Okagbare of Nigeria ran a personal-best 10.93 in another heat.
Jeter will be joined in Saturday's semifinals by teammates Tianna Madison — whose 10.97 was .01 off her season best — and a slow-starting Allyson Felix (11.01). Jeter dashed past reporters without discussing her performance, but other athletes said the Mondo track had helped them fly and fans' enthusiasm had kept them aloft.
"It's a very fast track. I love it. I loved the crowd," said Kerron Clement, whose season-best 48.48 in the first round of the 400 hurdles led all three Americans into Saturday's semifinals. "The crowd's great on the first day. I'm pretty impressed by that."
Rain was falling Friday morning when Sanya Richards-Ross ran a strategically low-powered 400 in 51.78 and advanced to Saturday's semifinal with Francena McCorory (50.78) and DeeDee Trotter (50.87). But Richards-Ross said she could still tell that the track would produce good times.
"My turnover felt really great on this track and I didn't feel like I was giving 100%, so I think it's going to give us a lot back when we're actually running very hard," she said.
Felix didn't like her start — "I completely missed it," she said — but liked the track. "It feels really good," she said. "It feels great to have it be a full stadium and feel all the energy. It's exciting to finally be underway."
Ennis felt the energy too. "I never knew I was going to run as fast, but to get a personal best on Day 1 is amazing," she said.
Ennis is the heptathlon leader through four events with 4,158 points, but Austra Skujyte of Lithuania set an Olympic heptathlon shotput record and is second with 3,974 points. Canada's Jessica Zelinka is third at 3,903, a point ahead of Ukraine's Lyudmila Yosypenko.
Hyleas Fountain of Daytona Beach, Fla., the Beijing heptathlon silver medalist, is fifth with 3,900 points. Sharon Day of Costa Mesa couldn't get her rhythm on the high jump and ranks 18th with 3,740 points entering Saturday's three final events. Chantae McMillan of Rolla, Mo., is 25th.
Discus thrower advances
Defending women's discus gold medalist Stephanie Brown Trafton of Galt, Calif., advanced to Saturday's final with the day's fifth-best throw, 212 feet, 10 inches, on her third and final attempt. The other U.S. competitors, Aretha Thurmond and Gia Lewis-Smallwood, didn't advance.
Leonel Manzano of Marble Falls, Texas, led the three Americans in the men's 1,500 into Sunday's semifinals. He was timed in 3:37.00, Matt Centrowitz of Arnold, Md., at 3:41.39 and Andrew Wheating of Eugene, Ore., at 3:40.92.... Evan Jager of Algonquin, Ill., the U.S. record holder in the 3,000 steeplechase, qualified for Sunday's final with a time of 8:16.61, second-best of the day. Donn Cabral of Glastonbury, Conn., also moved on but Kyle Acorn of Mesa, Ariz., didn't advance.
Long jumper Marquise Goodwin of Dallas led his qualifying group with a leap of 26 feet, 71/4 inches to reach Saturday's final. Will Claye of Phoenix also advanced with a jump of 26-23/4. But George Kitchens Jr. of Augusta, Ga., was eliminated.
Kibwe Johnson of Sacramento qualified for the hammer throw final with a season-best toss of 253-2. A.G. Kruger of Ashland, Ohio, was eliminated…. Amanda Smock of Melrose, Minn., the lone U.S. entrant in the women's triple jump, didn't advance past the qualifying round.