Juan Manuel Marquez vs. Juan Diaz (1st meeting)
2009-02-28 : Juan Manuel Marquez 134¼ lbs beat Juan Diaz 134½ lbs by TKO at 2:40 in round 9 of 12
- Location: Toyota Center, Houston, Texas, USA
- Referee: Rafael Ramos
- Judge: Levi Martinez 76-76
- Judge: Duane Ford 75-77
- Judge: Max DeLuca 77-75
- World Boxing Organization Lightweight Title (Vacant)
- World Boxing Association Lightweight Title (Vacant)
- International Boxing Organization Lightweight Title (1st defense by Diaz)
--- 2009 Boxing Writers Association of America Fight of the Year ---
--- 2009 Ring Magazine Fight of the Year ---
- Juan Manuel Marquez came in ranked as the # 2 fighter pound-for-pound and the # 1 lightweight in the world by The Ring Magazine. Juan Diaz came in as the # 2 lightweight in the world by the same publication.
- Marquez defends his Ring Magazine Lightweight World Title.
- Other fighters in attendance included Bernard Hopkins, Oscar De La Hoya and Shane Mosley.
- In Round 5, Marquez developed a small cut, from a punch, in the corner of his right eyelid.
- In Round 8, a left uppercut opened a bad cut on the the right eyelid of Juan Diaz. He was latter wobbled in the same round from another left uppercut.
- At 2:16 of Round 9, a combination sparked by a right hook and finished with a left uppercut sent Diaz falling forward and down to all fours and underneath the bottom rope. He was up at the count of four and received a standing eight-count.
- At 2:34 in Round 9, a tremendous right uppercut dropped Diaz flat on his back in the center of the ring. Without beginning a count, the referee immediately waved and end to the bout.
- Diaz officially announced his retirement on June 13, 2011.
- In the post-fight interview with HBO's Max Kellerman, Marquez said that he would like to fight Floyd Mayweather Jr. since, his first choice, Manny Pacquiao said he was not interested in a third meeting. Either way, Marquez said he would likely move up in weight class for his next fight.
- "What you just saw was a really good young fighter knocked out by a great old fighter." - HBO's Max Kellerman
- "February twenty-eighth is a little early to proclaim something the Fight of the Year, but good luck to the rest of the sport in producing something that good or that significant." - HBO's Jim Lampley