Tyson Gay and Asafa Powell will go head to head over 100 metres at the Aviva London Grand Prix on July 13.
The second and third fastest men of all time will meet at Crystal Palace 23 days before a potential rematch in the Olympic final.
Gay, who has battled back from terrible injury problems, won the United States trials in 9.86 seconds last week, while Powell, the former world record holder, finished third behind Yohan Blake and Usain Bolt in the Jamaican trials.
They will both be looking to send out a warning to Blake and Bolt, who have run 9.75secs and 9.76s respectively this year, ahead of the Olympics.
Gay said: "I haven't raced much this year and I'm feeling better each time out there on the track.
"My body is getting closer to where I want it to be. I've shown over the years that through all of the injuries, I'm a fighter, and I hope to be fighting for that Olympic gold in London later this summer."
Powell, 29, added: "This is a big year for me. I'm not getting any younger but there's a lot more to come from me. I've learned a lot from past major championships. I don't take anything for granted and I'm working as hard as ever. I know that I'm capable of running 9.8, 9.7, 9.6, so all that I'm focusing on is myself.
"I'm looking forward to taking on Tyson. It's good to have him back and it's going to make for a very competitive Olympic Games.
"Hopefully the world will be able to see the four fastest men ever going head-to-head in the 100m final in August in London, what a race that would be."
