PHILADELPHIA — The U.S. didn't let a lost shoe slow it down.

American sprinters won four of six races billed as "The US vs. The World" at the Penn Relays on Saturday, beating rival Jamaica to win both the men's and women's 400- and 1,600-meter relays.

In the women's 1,600, the U.S. team of Monica Hargrove, Natasha Hastings, Allyson Felix and Sanya Richards won in 3 minutes, 23.08 seconds after Hastings lost her left shoe during the exchange with Hargrove and ran the entire leg with a bare foot.

"I will say when it did come off, I thought about stopping," Hastings said. "Then I thought about everyone else and I thought it's just not about me. So knowing who I was running with and being in this arena, I couldn't stop. I had to go."

The U.S. team of Kerron Clement, Angelo Taylor, David Neville and LaShawn Merritt won the men's 1,600 in 2:59.78.

Several hour earlier, the memory of dropped batons at the Beijing Olympics fueled the American 400 teams.

Shawn Crawford, Walter Dix, Travis Padgett and Darvis Patton took the men's race in 37.92 ahead of another American team with Jamaica finishing ninth after anchor Asafa Powell pulled up at the end of the race.

Powell was doing fine before the race and wanted to see how his left leg would hold up, Powell's agent, Paul Doyle, said in a statement. The Jamaican star hadn't competed in over a month.

Crawford was not involved in the men's race in Beijing where Tyson Gay and Patton failed to make a clean exchange, but was still glad to help the U.S. gain a measure of redemption.

"The thing was just developing chemistry among the four of us," he said. "I'm not saying it's a revenge thing, but it's nice a defend and win on your home turf."

The women quickly followed suit with Lauryn Williams, Allyson Felix, Mechelle Lewis and Carmelita Jeter winning in 42.40 ahead of runner-up Jamaica, a victory that also helped ease memories of a botched baton exchange in Beijing.

"It's a great season starter for both the men and the women's teams," Jeter said. "It's good for both of the teams, the men and the women, to be excited about this year. To forget about '08 and go into '09 with aggression, with confidence and ready to run, and this is going to be a great year for the USA team and we're hungry right now."

Jamaica did draw first blood, setting a record in the rarely contested sprint medley in the second of the USA vs. the World races.

Sheri-Ann Brooks, Rosemarie Whyte, Moya Thompson and Kenia Sinclair finished in 3:34.56 to ignite a huge crowd of supporters. They cut nearly 3 seconds off the previous mark of 3:37.16 set by USA Blue at the 2006 Penn Relays.

The event — a pair of 200 legs with a 400 and an 800 — is rarely held, mainly in showcase events like the Penn Relays and is not officially recognized by the International Amateur Athletics Federation.

"We didn't even know the team we were going to run," said Sinclair, who ran the final leg in a blistering 1:57.43 despite it being her first 800 of the season. "I think this was our best chance of winning a relay today against the USA. We just wanted to start it off good for the rest of the team."

Earlier, Tennessee set an American record in the 3,200 to complete a rare relay triple.

The team of Kimarrra McDonald, Chanelle Price, Sarah Bowman and Phoebe Wright finished in 8:17.91 to beat Maryland Eastern Shore and break the mark of 8:18.78 set by Michigan at the 2007 Penn Relays.

Tennessee is just the third program and sixth women's team to take the distance medley and the 6,000- and 3,200-meter events in the 115-year history of the meet. North Carolina's women were the last to do it, in 2003.

"Our focus wasn't on the record," said Bowman, who anchored the two previous wins this weekend. "It was again about competing. If you get too caught up in times it messes you up. We we're like just go out there and compete hard."