Mysterio made his in-ring return at SummerSlam on August 26, 2007, defeating Guerrero, after Guerrero obsessed over Mysterio's return as well as wanting to injure Mysterio again. On the August 31 episode of "SmackDown!", Mysterio won a "Championship Competition" to become the number one contender for the World Heavyweight Championship, defeating Batista and Finlay. On the September 7 episode of "SmackDown!", Mysterio had an "I Quit" match with Guerrero, which he won after hitting Guerrero's knee with a steel chair repeatedly in a similar manner to which Mysterio had been put out of action, to end the feud. Mysterio then began a feud with The Great Khali, which led to a World Heavyweight Championship match at Unforgiven. The match was later made a Triple Threat match, also involving Batista, who won it.