Allyson Felix showed she was getting back to her best by winning the 200 metres at the Bislett Games in Oslo, Norway, on Wednesday, while there was further American success in the long jump, triple jump and shot put.
Felix, the Olympic and three-time world champion, won in 22.73 seconds ahead of Jodie Williams of Britain in 22.97, and Myriam Soumare of France in 22.98. Soumare earlier won the 100.
"I just wanted to work on some of the things I'd been doing in practice. The speed isn't quite there, but it's coming and hopefully the rest of the season will just keep progressing," said Felix, who endured an injury-plagued 2013.
"It's going to take me a little bit to get back to that top form but I'm just blessed to be running on track. This is what I love so I'm having fun out there."
Murielle Ahoure of Ivory Coast, expected to be Felix's main challenger, could manage only fifth.
Tianna Bartoletta of the U.S. jumped a year-leading 7.02 metres to win the women's long jump, Will Claye led an American 1-2 in the men's triple jump, and Joe Kovacs won the shot put.
"I can tell you I would not have thought before the competition that 21.14 would be enough to win," Kovacs said.
Soumare produced a season-best 11.18 to win the 100 ahead of Americans Lekeisha Lawson and Muna Lee.
"Very good evening for me," Soumare said. "But I'm tired, believe me."
With Usain Bolt still working his way back from a foot injury, Trinidad and Tobago's Richard Thompson won the men's 100 in a slow 10.02 seconds, ahead of Frenchman Jimmy Vicaut, and Britain's Adam Gemili. Former world champion Kim Collins was fourth.
Frenchman Pascal Martinot-Lagarde ran a year-leading 13.12 to win the 110 hurdles ahead of Jamaican Andrew Riley and Russia's Sergey Shubenkov.
Another Frenchman, Renaud Lavillenie, won the men's pole vault for his third win from three starts in Oslo.
European 1,500 champion Henrik Ingebrigtsen set a Norwegian record in the Dream Mile, but could finish only fourth, behind last year's winner Ayanleh Souleiman of Djibouti, who won in 3:49.49.
"A perfect race for me," Souleiman said.
Blanka Vlasic finished second in the high jump on her season debut with 1.98 metres. The Croatian performed a celebratory dance on clearing it, but the win went to Mariya Kuchina, who cleared it in fewer attempts - a personal best for the Russian.
Yenew Alamirew of Ethiopia won the 5,000, Jairus Kipchoge Birech of Kenya the 3,000 steeplechase, Jamaica's Kaliese Spencer made it three in a row in the women's 400 hurdles, Kenya's Eunice Jepkoech Sum won the 800, and Jamaica's Novlene Williams-Mills the 400.