After nearly 13 years as a professional fighter, Seth Petruzelli will step away from the cage.

The 33-year-old Petruzelli (14-8 MMA, 1-2 BFC) made the announcement Friday morning on his Facebook page. His announcement comes following a knockout loss to Muhammed Lawal on Wednesday night at Bellator 96.

“The Silverback” goes out on a two-fight skid, with both losses coming in the first round as part of Bellator’s most recent two light heavyweight tournaments.

Petruzelli, in his online statement, said has has lost some of the drive to fight the way he used to.

“I want to thank my family, friends, fiancée and fans for being by my side these past 13 years plus of my MMA career. Every time I fought it was to please and excite you but most of all make you proud of me. Up until a couple years ago it pleased and excited me as well. That is where I went wrong, for the past couple years I have been fighting for the wrong reasons, I don’t have the desire or drive to fight like I used to and the past couple fights have shown it. So at this point in my life I would like to officially announce my retirement from the sport of MMA. Competing has been a part of my life since I was 6 years old, now I would like to put more of an effort into seeing my students/fighters do the same and making my gym grow and flourish. MMA has taken me around the world, let me meet the best and worst of people and made me feel like the brightest star but also like a black hole at times … and I have no regrets because I did it all my way.

The Floridian fought on the first WEC card back in 2001 and was submitted by Gan McGee. But he then went on a six-fight win streak over more than two years that culminated with a King of the Cage win over UFC Hall of Famer Dan Severn.

That got him a shot on Season 2 of “The Ultimate Fighter,” where he competed at heavyweight under coach Rich Franklin alongside eventual winner Rashad Evans. A year after the show aired, Petruzelli got his first official crack at the UFC, but lost a unanimous decision to Matt Hamill – though the two won “Fight of the Night” honors for the bout at “UFC Fight Night: Ortiz vs. Shamrock 3.”

After a knockout win outside the promotion, Petruzelli was brought back to the UFC to fight Wilson Gouveia in April 2007. And once again, despite a second-round submission loss, he took home a “Fight of the Night” bonus check.

After a four-fight win streak, Petruzelli again was brought back to the UFC after more than three years away. But he still couldn’t get that elusive win for the promotion with a submission loss to Ricardo Romero at UFC 116 and a TKO loss to Karlos Vemola at UFC 122.

But as part of that four-fight streak, Petruzelli picked up the win he will go down in history as best known for. On arguably the shortest notice in recent high-level MMA memory, he stepped in on just a few hours notice the day of the fight to face “Kimbo Slice,” Kevin Ferguson, when Ken Shamrock pulled out with a cut.

And on a nationally televised EliteXC show on CBS, Petruzelli upset the famed street fighter in just 14 seconds with a TKO.

In 2011, Petruzelli signed with Bellator and won his debut with the promotion with a first-round knockout of former UFC heavyweight champ Ricco Rodriguez. But in the Season 8 205-pound tournament quarterfinals, he was stopped by Jacob Noe in January. And in Wednesday’s “Summer Series” debut in Thackerville, Okla., he was stopped with a one-punch KO by “King Mo” in the four-man tourney’s semifinals.

For more on Bellator 96, check out the MMA Events section of the site.

(Pictured: Seth Petruzelli and Muhammed “King Mo” Lawal)