On October 1, 2011, a 31-year-old Sebastian Sylvester (34-4-1, 16 KOs) and a 26-year-old Polish boxer Grzegorz Proksa (25-0, 18 KOs) met in the ring in a middleweight bout.
Sylvester came in to the fight on a 1-fight losing streak with a 41% KO rate, and was fighting after a gap of 4 months and 24 days. Proksa was on a 25-fight win streak with a 72% KO rate, and fighting after a layoff of 3 months and 8 days.
Grzegorz Proksa stopped Sebastian Sylvester via RTD in the 3rd round. Proksa improves his record to 26-0 (19 KOs), while Sylvester adds a loss to his record at 34-5-1.
On May 7, 2011, the 30-year-old IBF middleweight world champion, Sebastian Sylvester (34-3-1, 16 KOs), faced a 30-year-old Australian boxer Daniel Geale (24-1, 15 KOs), in a title defense fight.
Sylvester came in to the fight on a 1-fight win streak with a 42% KO rate, and was fighting after a gap of 6 months and 7 days. Geale was on a 3-fight win streak with a 60% KO rate, and fighting after a layoff of 6 months and 7 days.
Daniel Geale defeated Sebastian Sylvester via split decision and wins the IBF title — in his first world-title fight. Geale improves his record to 25-1, while Sylvester adds a loss to his record at 34-4-1.
On November 1, 2008, a 28-year-old Sebastian Sylvester (29-2, 14 KOs) got a shot at the middleweight WBA title held by 29-year-old fellow German boxer Felix Sturm (30-2-1, 13 KOs).
Sylvester came in to the fight on a 8-fight win streak with a 45% KO rate, and was fighting after a gap of 6 months and 20 days. Sturm was on a 2-fight win streak with a 39% KO rate, and fighting after a layoff of 3 months and 25 days.
Felix Sturm defeated Sebastian Sylvester via unanimous decision and successfully defended his WBA middleweight title. Sturm improves his record to 31-2-1, while Sylvester adds a loss to his record at 29-3.
On June 3, 2006, a 25-year-old Sebastian Sylvester (21-1, 9 KOs) and a 30-year-old Finnish boxer Amin Asikainen (17-0, 13 KOs) met in the ring in a middleweight bout.
Sylvester came in to the fight on a 21-fight win streak with a 40% KO rate, and was fighting after a gap of 1 month and 12 days. Asikainen was on a 17-fight win streak with a 76% KO rate, and fighting after a layoff of 29 days.
Amin Asikainen stopped Sebastian Sylvester via TKO in the 8th round. Asikainen improves his record to 18-0 (14 KOs), while Sylvester adds a loss to his record at 21-2.
On May 26, 2002, a 21-year-old Sebastian Sylvester (debutant) and Yuri Zaytsev met in the ring.
Sebastian Sylvester lost to Yuri Zaytsev via KO in the 1st round, making an unsuccessful professional debut.