Olympic heptathlon champion Jessica Ennis-Hill expressed satisfaction after firing a warning to her Rio rivals in London on Friday night.
The 30-year-old, back at the Olympic Stadium where she memorably took heptathlon gold as the poster girl of London 2012, clocked 12.76 seconds to finish third in her 100 metres hurdles heat at the Muller Anniversary Games.
As Kendra Harrison, who failed to qualify for the United States' Olympics team, beat a 28-year-old world record in the final in 12.20secs, Ennis-Hill had to settle for eighth in 13.04 after clattering a hurdle.
"I was really pleased. I have one race in the hurdles (in the heptathlon)," Ennis-Hill said.
"I ran the fastest time of the season, third race in the hurdles. I'm so happy to run a season's best and it makes me confident with Rio next.
"I would've liked to have gone quicker in the final, but just smacked a hurdle really bad and lost all momentum and that was it."
Ennis-Hill's second run was still quicker than her prior season's best of 13.10, while her earlier performance was the second best time of her career, slower only than her 12.54 set en route to London 2012 gold.
It was also a clear sign the Sheffield athlete is very nearly back to her best, two years after giving birth to her son Reggie and despite an Achilles problem earlier in the season.
Canada's Brianne Theisen-Eaton, the world leader in the heptathlon this year, will know that the Briton, who last month recorded her best heptathlon score since London 2012 with 6,733 points, is likely to now be the woman to beat in Rio.
Katarina Johnson-Thompson showed her heptathlon medal potential ahead of Rio with an outdoor personal best in the high jump.
The 23-year-old from Liverpool cleared 1.92m at the second attempt - equalling her PB set in Gotzis, Austria in May - and then soared over 1.95m at the second attempt, too, entering new territory.
The Briton had three attempts at 1.98m, but was unsuccessful.
It meant the British record of 1.97m held by Isobel Pooley, who will miss Rio through injury, survived another day.
"I'm so pleased with that. It's the best I've felt all season," Johnson-Thompson said.
"Hopefully I can jump well in Rio and get some good points."
Morgan Lake also cleared 1.92m at the third attempt, setting a season's best, but had three failures at 1.95m as she tried to set a personal best.
Ennis-Hill and Johnson-Thompson compete in the long jump on Saturday.
Ennis-Hill, who set a personal best of 6.63m in Ratingen, Germany in June, said: "It would be nice to try to do something similar distance-wise."
Johnson-Thompson, who has had some jittery long jump showings of late, added: "I've been up for the long jump all season. I'm happy. I can't wait for it."