While Rey Mysterio and Chavo Guerrero once had a family-like bond, their SummerSlam histories are quite different. Mysterio has competed in SummerSlam three times -- in 2002, 2004 and 2005 -- whereas Guerrero has never before been in a match at the Biggest Party of the Summer. There's a first time for everything, and Guerrero will come out of retirement for SummerSlam, ready to go up against his former close friend, Mysterio.

In Mysterio's SummerSlam debut in 2002, he faced Olympic Gold Medalist Kurt Angle at the Nassau Coliseum in Long Island, N.Y. During the exciting match, Mysterio landed an impressive 619 and a West Coast Pop on Angle. Ultimately Angle came up the winner, though, forcing Mysterio into an ankle lock submission. Mysterio couldn't grab the rope and had to tap out, giving Angle the victory.

At SummerSlam 2004 in Toronto, Canada, Mysterio teamed up with Paul London and Billy Kidman for a 6-Man Tag Match against the Dudleys (Bubba Ray, D-Von and Spike). While Mysterio faced all three of the Dudleys in the ring, Kidman was pummeled by the Dudley Death Drop from Bubba Ray and D-Von, allowing Spike to score the pinfall victory, putting Mysterio's SummerSlam record at 0-2.

Finally, at last year's SummerSlam, Mysterio faced the late, great Eddie Guerrero in a Ladder Match. The exhausting, high-risk match went back and forth between the two, and at one time, both were at the top of the ladder. In the end, Mysterio managed to scale the ladder quicker than the WWE Hall of Famer and won the match.

Will Mysterio improve his 1-2 SummerSlam record, or will Chavo Guerrero earn a victory during his SummerSlam debut? This match up is destined to be an emotional one since Chavo Guerrero's betrayal is the reason Mysterio doesn't hold the World Championship anymore. Find out how Mysterio and Chavo Guerrero's bitter rivalry ends at the Biggest Party of the Summer, live from Boston, this Sunday at 8 p.m., only on per-per-view.