Rey Mysterio Jr. was one of the best cruiserweights in the world when he showed up in America for ECW. While he was significantly undersized compared to some of his larger colleagues, he could do things that other cruiserweights only dreamed of. It didn't take long for WCW to come calling, and Mysterio became the face of its cruiserweight division.

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Mysterio wasn't able to move above the cruiserweight level, although he did have some tag team title reigns. However, when he moved to WWE, the unthinkable happened. The undersized, underdog moved to the top and became a world champion. Here is a look at Rey Mysterio's five best matches in WWE and his five best from WCW.

10 WWE: Rey Mysterio Vs. Eddie Guerrero (SmackDown, Nov. 14, 2002)

If there is anyone in WWE that brought out the best of Rey Mysterio, it was his close friend Eddie Guerrero, someone he rose the ranks with and against.

There was interference here, but WWE was smart and had the interference end without the match finishing. After fifteen minutes, Guerrero picked up the win by submission. These two men had one of the best feuds of 2002.

9 WCW: Rey Mysterio Vs. Eddie Guerrero (Hallowen Havoc, 1997)

It wasn't just in WWE that Eddie Guerrero and Rey Mysterio tore down the house. The two also had some fantastic matches in WCW. They faced off at Halloween Havoc in 1997, and this was for the WCW Cruiserweight Championship. If Rey lost, he also lost his mask.

The match went for thirteen minutes, and this was easily a five-star match that saw Rey reverse the Splash Mountain into a Rana for the win and the title.

8 WWE: Rey Mysterio & Edge Vs. Chris Benoit & Kurt Angle (No Mercy, 2002)

In 2002, WWE had some of the best wrestlers in the world on SmackDown, and that included Rey Mysterio. At No Mercy in 2002, Mysterio was involved in a tag team match where he teamed with Edge to battle Chris Benoit and Kurt Angle.

This was to fill the vacant tag team titles, and they turned in a five-star match that ended when Angle made Edge tap out to make Angle and Benoit the new champions.

7 WCW: Rey Mysterio Vs. Juventud Guerrera (Thunder, Jan. 15, 1998)

When it came to the WCW Cruiserweight Championship, WCW loved to have multi-men matches above all. There were a ton of Luchadores that the company brought in and used together almost too much. However, when WCW put the best of them together in a one-on-one match, magic happened.

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On an episode of Thunder, WCW put the two best against each other for the Cruiserweight Championship. Juventud Guerrera came in as the champion, and after nine minutes of non-stop action, Rey Mysterio hit the Hurracanrana for his third title win.

6 WWE: Rey Mysterio Vs. Kurt Angle (SmackDown, Feb. 10, 2005)

In 2005, the SmackDown roster was turning in some of the best matches in the entire company. That was on display in the match, when Kurt Angle battled Rey Mysterio in the quarterfinals of the WWE World Championship number one contender's tournament.

The two put on a fantastic match that ended when Angle hit the Angle Slam and locked in the Ankle Lock for the win, with both men looking like stars.

5 WCW: Rey Mysterio Vs. Billy Kidman Vs. Juventud Guerrera (Starrcade 1998)

One thing that WCW loved to do with its cruiserweight title was to have multi-men matches and throw all their smaller guys into the ring at the same time and have them pull off awe-inspiring moves for 10-15 minutes.

At Starrcade 1998, Billy Kidman put his title on the line against Rey Mysterio Jr. and Juventud Guerrera. They went for fourteen minutes, and Kidman pinned Juvi in a great match.

4 WWE: Rey Mysterio Vs. Chris Jericho (The Bash, 2009)

Chris Jericho wrote in his biography about how he met Rey Mysterio for the first time and through he was a kid. At the time, the two were top cruiserweight stars in WCW, where both men were underbooked. They then moved on to WWE, and both became world champions.

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In 2009, they were both former champions and future Hall of Fame superstars. At The Bash 2009, Jericho brought in his Intercontinental Championship and put it on the line against Mysterio's mask. The two fought for fifteen minutes before Mysterio hit the Springboard Splash to win his title back.

3 WCW: Rey Mysterio Vs. Billy Kidman (Nitro, March 15, 1999)

Billy Kidman was one of the top WCW Cruiserweight Champions of all-time. There are two multi-man matches on this list that had Kidman picking up wins while Mysterio was involved but was not involved in the loss.

Then, the two men finally battled in a one-on-one match. In this case, no one else could cost Rey the match, and Mysterio hit the sit-out bulldog for the win and the title.

2 WWE: Rey Mysterio Vs. John Morrison (SmackDown, Sept. 4, 2009)

In 2009, Rey Mysterio was a former world champion and a legend in wrestling. On the other hand, John Morrison was one of the up-and-coming superstars and was proving to be an exciting in-ring talent.

On SmackDown, Mysterio came in as the Intercontinental Champion and put his title on the line against Morrison. The two put in a long, fantastic match, and Morrison won with the Starship Pain for the title.

1 WCW: Rey Mysterio Vs. Billy Kidman Vs. Juventud Guerrera Vs. Psicosis (Souled Out, 1999)

While WCW was starting to slip up in 1999, there were still some great moments thanks to the talent putting on fantastic matches despite the shaky booking.

In yet another multi-man match for the cruiserweight title, four men were fighting at Souled Out 1999. This was a four-corners match, and once again, it was Kidman who won, pinning Juvi to retain the title. All four men looked tremendous, and this match stole the show.

NEXT: The 5 Best (& 5 Worst) WCW World Title Changes In Nitro History