Lesnar defended his Universal Championship against Rollins on Sunday in the main event, a rematch from WrestleMania 35 in April.
Rollins fought through broken ribs and did everything he could to weaken The Beast throughout the match. Rollins was able to land on his feet after Lesnar lifted him up for a German Suplex, allowing him to nail his rival with a Curb Stomp.
Rollins would keep finding ways to keep Lesnar at bay and survive the match, including jumping onto Lesnar to put the champion through the announcer's table.
Rollins overcame all the odds and escaped from Lesnar's F-5 to land another Curb Stomp to become the new Universal Champion. Rollins celebrated by holding up his championship as fireworks erupted.
Becky Lynch defended her Raw Women's Championship against Natalya in a grueling Submission Match. The women immediately started brawling to start the bout and continued to be aggressive throughout the contest.
Lynch would try to use Natalya's own submission hold the Sharpshooter to win with Natalya repaying the favor later on by using Lynch's Dis-Arm-Her hold.
Natalya would eventually lock in her Sharpshooter which Lynch was able to escape from and administer the Dis-Arm-Her to win the match.
Orton, as Kingston leaped at him from the top turnbuckle, suddenly hit the champion with an impressive RKO. Kingston, while dazed, rolled out of the ring in order to avoid being pinned. Orton followed behind and started mocking the high-flyer in front of his wife and kids who were seated at ringside.
The disrespect towards his family woke up Kingston who began fighting back. The exchange took too long, however, causing the referee to count-out out both competitors and end the match in a draw. Kingston, who gets to keep his WWE Championship, continued to assault Orton using a kendo stick before he knocked The Viper out with a Trouble in Paradise.
Stratus was given a hometown hero's welcome from the Toronto crowd and proved that she can still compete at a high-level despite being retired.
Stratus pulled out all the stops against Flair, using her Stratusfaction Bulldog to try and win along with Flair's own move, The Figure-Eight. Flair wouldn't stay down and eventually took the living legend out by locking in the Figure-Eight, causing Stratus to tap out.
Other moments from SummerSlam included Cruiserweight Champion Drew Gulak defeating Oney Lorcan; Hall of Famer Edge returning to Spear Elias; Women's Tag Team Champions Alexa Bliss and Nikki Cross defeating The IIconics; Goldberg quickly defeating Dolph Ziggler; United States Champion AJ Styles defeating Ricochet; Smackdown Women's Champion Bayley defeating Ember Moon; Kevin Owens defeating Shane McMahon to keep his job; and Bray Wyatt in his Fiend form defeating Finn Balor.
SummerSlam was the in-ring return of Wyatt after he was away from competition for months. The Fiend completely overpowered Balor and won the match after making Balor pass out from the Mandible Claw.