Conversation so far:
Did Rey Mysterio ever win a title at the cruiserweight division?
On the July 8 episode of WCW Monday Nitro, Rey Mysterio defeated Malenko to win his first Cruiserweight Championship.
Was Rey Mysterio's first Cruiserweight Championship win the only one he won at that weight level?
Rey Mysterio defeated Guerrero to win his second Cruiserweight Championship. He won it a third time against Juventud and a fourth time against Jericho.
Did Rey Mysterio move up a weight class after performing at the cruiserweight?
Mysterio got his first shot at the WCW World Heavyweight Championship in 1999 and started competing at this level starting in 2005.

Question: Did he start his career in the Cruiserweight division?
Self-contained rewrite: Did Rey Mysterio start his career in the Cruiserweight division?