BOSTON — Chael Sonnen snapped a two-fight losing streak with a first-round submission victory over former Ultimate Fighting Championship light heavyweight champion Mauricio "Shogun" Rua on Saturday night at the TD Garden in a scheduled five-round non-title bout.
Sonnen (29-13-1) earned the victory at 4:47 of the first round when he applied a guillotine choke.
Rua, from Brazil, dropped to 21-8.
Midway through the round, Sonnen took Rua to the mat with a double underhook throw. After he landed several head strikes while on top of Rau, Sonnen turned Rua over with Rua's head locked under his arm, forcing Rau to tap out.
The 36-year-old Sonnen, from West Linn, lost by technical knockout in his last two fights to Anderson Silva and Jon Jones.
The 31-year-old Rua dropped two of his previous three bouts, with decision losses to Dan Henderson and Alexander Gustafson and a TKO victory over Brandon Vera.
The bout was the main event of the debut of the UFC Fight Night Series on Fox Sports 1.
In the co-main event, heavyweight Travis Browne of Albuquerque, N.M., knocked out Alistair Overeem of the Netherlands at 4:08 of the first round in a scheduled three-round bout.
Browne dropped Overeem with a left front kick to the face. Browne followed up with three right hands to the head before referee Mario Yamasaki stopped the fight.
Brown improved to 15-1-1. Overeem dropped to 36-13, with one no contest.