1. Kurt Angle
Kurt Angle is the only superstar to defeat Brock Lesnar clean via ‘submission’ (Oh it’s true, it’s damn true). At the first ever Smackdown brand exclusive pay-per-view Vengeance in 2003, Lesnar defended his WWE Championship in a Triple Threat match against Big Show and Kurt Angle which Kurt went on to win.
Lesnar and Angle both were babyfaces and friends at that time and continued their friendly rivalry for the title. However Vince McMahon inserted himself into the storyline and he faced Lesnar in a steel cage match with Angle as special guest referee. Amidst the match, Lesnar passed out due to a staged backstage incident and McMahon was about to pin him.
But Kurt refused to allow McMahon to win in that way. Both McMahon and Angle were arguing just when Lesnar woke up and attacked Angle with an F5 turning heel in the process.
At SummerSlam 2003 both Lesnar and Angle faced off for the WWE Championship in which Lesnar tapped out to the Ankle Lock. This loss was not only clean but made Lesnar look weak as he submitted.
Angle went on to win the match despite the odds being stacked against him, Vince McMahon attacked him amidst the match when the referee was down but Angle went on to retain the championship.