Former middleweight title challenger Nathan Marquardt (Pictures) will take on Martin Kampmann (Pictures) in a main-card bout at UFC 88 “Breakthrough” on Sept. 6 at Philips Arena in Atlanta. UFC representatives made the bout official Thursday.

Marquardt (26-8-2) last appeared at UFC 85 in June when he dropped a split decision to rising Brazilian contender Thales Leites (Pictures). An illegal second-round knee and another controversial point deduction for strikes to the back of the head in the third cost Marquardt the decision, as he lost for just the second time in seven trips inside the Octagon.

One of the middleweight division’s most accomplished fighters, the soft-spoken 29-year-old former King of Pancrase holds victories against current EliteXC lightweight contender Yves Edwards (Pictures), one-time Pride middleweight grand prix champion Kazuo Misaki (Pictures) and Daiju Takase (Pictures) -- one of only two men to finish reigning UFC middleweight king Anderson Silva (Pictures). Marquardt’s own encounter with Silva went much differently, as he succumbed to strikes against the Brazilian at UFC 73 last summer.

Based at Xtreme Couture Mixed Martial Arts in Las Vegas, Kampmann (13-1) returned from a career-threatening knee injury and submitted Jorge Rivera (Pictures) with a first-round guillotine choke at UFC 85 on June 7 in London. The talented 26-year-old Dane will enter his match with Marquardt on an impressive nine-fight winning streak; his list of victims includes Leites, against whom he earned a unanimous decision in November 2006. A proven finisher, Kampmann has secured six of his 13 career wins by KO or TKO and four more by submission.

A light heavyweight showdown pairing former champion and future Hall-of-Famer Chuck Liddell (Pictures) with the undefeated Rashad Evans (Pictures) will headline UFC 88.