Padilla was an interesting case. He started as a lightweight, suffered a kO loss in an ESPN Championship fight, looking rather mediocre in the process. (remember those ESPN tournaments?), then took over five years off. He came back at 140 and utilized an insane work rate and conditioning to go on an impressive streak, winning the WBO title and making several defenses. Then, he got a head injury sparring with Shane Moseley and it was suddenly over.
Padilla grew the myth of Mosley who at the time was coming up the ranks. Padilla was a good fighter and Mosley ruined his career in sparring.
Interestingly, he is also the cousin of former perennial baseball all-star Michael Young of Texas Rangers fame. One of my favorite players.