On September 27, 2008, a 36-year-old Guillermo Jones (35-3-2, 27 KOs) got a shot at the WBA cruiserweight title held by 37-year-old German boxer Firat Arslan (29-3-1, 18 KOs).
Jones came in to the fight on a 4-fight win streak with a 67% KO rate, and was fighting after a gap of 1 year, 2 months, and 20 days. Arslan was on a 11-fight win streak with a 54% KO rate, and fighting after a layoff of 4 months and 24 days.
Guillermo Jones stopped the champion via TKO in the 10th round of the 12-round world-title fight, winning the first world title of his career, and is crowned the new WBA cruiserweight champion. Jones improves his record to 36-3-2 (28 KOs), while Arslan adds a loss to his record at 29-4-1.
On November 5, 2011, the 39-year-old WBA cruiserweight world champion, Guillermo Jones (37-3-2, 29 KOs), faced Michael Marrone, in a title defense fight.
Jones came in to the fight on a 6-fight win streak with a 69% KO rate, and was fighting after a gap of 1 year, 1 month, and 3 days.
Guillermo Jones stopped Michael Marrone via TKO in the 6th round of the 12-round world-title fight, and successfully defended his WBA cruiserweight title. Jones improves his record to 38-3-2 (30 KOs)
On November 23, 2002, a 30-year-old Guillermo Jones (29-2-1, 22 KOs) got a shot at the cruiserweight WBO title held by 35-year-old British boxer Johnny Nelson (42-12-1, 28 KOs).
Jones came in to the fight on a 7-fight win streak with a 68% KO rate, and was fighting after a gap of 4 months and 10 days. Nelson was on a 17-fight win streak with a 50% KO rate, and fighting after a layoff of 7 months and 17 days.
The fight ended in a split decision draw and both the fighters added a draw to their respective records — Jones is now 29-2-2 and Nelson, 42-12-2.
On September 3, 2005, a 33-year-old Guillermo Jones (32-3-2, 25 KOs) and a 30-year-old Guyanese boxer Wayne Braithwaite (21-1, 17 KOs) met in the ring in a cruiserweight bout.
Jones came in to the fight on a 1-fight win streak with a 67% KO rate, and was fighting after a gap of 3 months and 13 days. Braithwaite was on a -1-fight win streak with a 77% KO rate, and fighting after a layoff of 5 months and 1 day.
Guillermo Jones stopped Wayne Braithwaite via TKO in the 4th round. Jones improves his record to 33-3-2 (26 KOs), while Braithwaite adds a loss to his record at 21-2.
On October 2, 2010, the 38-year-old WBA cruiserweight world champion, Guillermo Jones (36-3-2, 28 KOs), faced Valery Brudov, in a title defense fight.
Jones came in to the fight on a 5-fight win streak with a 68% KO rate, and was fighting after a gap of 2 years and 5 days.
Guillermo Jones stopped Valery Brudov via TKO in the 11th round of the 12-round world-title fight, and successfully defended his WBA cruiserweight title. Jones improves his record to 37-3-2 (29 KOs)
On November 29, 1997, a 25-year-old Guillermo Jones (21-1, 18 KOs) and David Noel met in the ring for the 2nd time, in a super-welterweight bout.
Jones came in to the fight on a 1-fight losing streak with a 81% KO rate, and was fighting after a gap of 2 months and 2 days.
In the rematch, Guillermo Jones stopped David Noel via TKO in the 1st round. Jones improves his record to 22-1 (19 KOs)
On February 2, 1996, a 23-year-old Guillermo Jones (13-0, 11 KOs) and José García met in the ring in a welterweight bout.
Jones came in to the fight on a 13-fight win streak with a 84% KO rate, and was fighting after a gap of 4 months and 15 days.
Guillermo Jones stopped José García via KO in the 1st round. Jones improves his record to 14-0 (12 KOs)
On January 6, 2007, a 34-year-old Guillermo Jones (33-3-2, 26 KOs) and Jeremy Bates met in the ring.
Jones came in to the fight on a 2-fight win streak with a 68% KO rate, and was fighting after a gap of 1 year, 4 months, and 3 days.
Guillermo Jones stopped Jeremy Bates via TKO in the 1st round. Jones improves his record to 34-3-2 (27 KOs)
On February 13, 1998, a 25-year-old Guillermo Jones (22-1, 19 KOs) got a shot at the super-welterweight WBA title held by Laurent Boudouani.
Jones came in to the fight on a 1-fight win streak with a 82% KO rate, and was fighting after a gap of 2 months and 15 days.
The fight ended in a majority decision draw and both the fighters added a draw to their respective records — Jones is now 22-1-1.
On May 21, 2005, a 33-year-old Guillermo Jones (31-3-2, 24 KOs) and Kelvin Davis met in the ring.
Jones came in to the fight on a 1-fight losing streak with a 66% KO rate, and was fighting after a gap of 1 month and 19 days.
Guillermo Jones stopped Kelvin Davis via TKO in the 4th round. Jones improves his record to 32-3-2 (25 KOs)