South Africa's Akani Simbine and reigning world 60m indoor champion Murielle Ahoure of Ivory Coast won 100 meters titles at Sunday's Boston Games athletics meet.
The unique event's feature races were contested on a portable 200m straightaway strip installed at the finishing area for the Boston Marathon.
Simbine, the reigning Commonwealth Games 100m champion, won his specialty in 9.92 seconds, .11 ahead of American Kendal Williams.
"A 9.92, that's good on this track," said Simbine, whose effort came following afternoon showers dampened the track.
Ahoure won the women's 100 in 11.09 with American Aleia Hobbs .02 back.
"I feel really rusty," Ahoure said. "I was so nervous."
World 2017 100m champion Tori Bowie, who tore a quadriceps muscle last year, was third in 11.22.
"Coming back from tearing my quad, Im off to an amazing start," Bowie said.
Reigning Olympic women's 400 champion Shaunae Miller-Uibo of Bahamas won the 150 meters in 16.37, her third Boston title in a row at the unusual distance, with Trinidad and Tobago's Michelle-Lee Ahye second in 16.60.
"It's always fun to come to Boston. I'm three for three," Miller-Uibo said. "I just hope to continue to improve this year. Things are falling into place slowly but surely."
American Noah Lyles was given a dubious bailout on a disqualification and took advantage to win the men's 150 in 14.69, beating Britain's Nethaneel Mitchell-Blake by 0.41 of a second.
What appeared even in slow-motion replay to be an obvious false start was instead ruled to be inconclusive evidence, allowing Lyles to race.
"What did the guy at the start say? Green card. Then it was a green card," Lyles said. "No time goal. We wanted to get this right for the 100 and 200. get a good start like the 100 and finish strong like the 200."
Britain's Zharnel Hughes, last year's European 100m champion, won the 200 in 20.00, beating Trinidad and Tobago's Kyle Greaux by 0.09.
"I just tried to finish myself strong," Hughes said. "I propeled through my finish and pushed hard to the line.
"I'm happy with that. This is my first 200 of the season. As the season goes along I'll get better."
Anastasia Le-Roy, a member of Jamaica's 2015 world champion women's 4x400 relay, won the women's 200 in 23.12, defeating American Lynna Irby by 0.12 to defend her title.
"It's fantastic," she said. "I was so excited to come back and run in the streets of Boston. You just have to finish strong."
- Ortega wins 110 hurdles -
Cuban-born Spaniard Orlando Ortega, the 2016 Rio Olympic 110 hurdles runner-up, won the 110 hurdles in 13.32 seconds, edging American Shane Brathwaite at the line by 0.01 for his third Boston win in a row in the event as he looks toward next year's Tokyo Olympics.
"That's amazing," Ortega said. "I'm very happy to be back here. I think I can go into every competition well. This is my big dream now, to go to Tokyo and be the best."
American Sharika Nelvis won the 100 hurdles in 12.65.
American Shamier Little, the 2015 world 400m hurdles runner-up running three days after she raced in Oslo, won the 200 hurdles in 25.88 seconds, .17 ahead of runner-up Ronda Whyte of Jamaica.
American Ajee Wilson, two-time world indoor runn-erup and 2017 outdoor bronze medalist at 800 meters, won the 600 in 1:26.3, edging Uruguay's Deborah Rodriguez by 0.6 of a second.
Reigning European 1,500m champion Marcin Lewandowski of Poland won the men's mile in 3:57.4, with American Drew Hunter edging Britain's Chris O'Hare for second with both clocked at 3:57.6.