Anthony Pettis finishes Gilbert Melendez at UFC 181

Anthony Pettis stopped Gilbert Melendez with a guillotine choke 1:53 into the second round, defending his lightweight championship at UFC 181 on Saturday night.

Pettis (18-2) dramatically finished the fight shortly after landing a front kick to the face of Melendez (22-4), who was staggered for the first time. Melendez attempted a takedown, but Pettis defended it and swiftly locked in the decisive choke to end his first title defense.

“I know how good I am, but a lot of people were questioning how good I am,” Pettis said.

Pettis hadn’t fought in 16 months, but came back from injuries for his first bout since winning his belt last year. The Milwaukee native returned from knee surgery with another demonstration of his impressive athleticism for his fifth consecutive victory.

Melendez was stopped for the first time in his lengthy MMA career, losing his second UFC title shot in two years.

“I’m only getting better,” Pettis said. “I’ve been working every day in the gym, and I’m still young in this game.”

Melendez took down Pettis twice in the opening minutes and kept the champion pinned against the cage for most of the first round. Pettis eventually broke into his array of kicks and spins, but they didn’t do much until he surprised Melendez with the front kick that rattled his skull.

Melendez appeared less sharp, and the sloppy takedown attempt quickly turned into an opportunity for Pettis, who leaped onto Melendez to finish.

“I wanted to test his chin, and I really didn’t get a chance,” Melendez said. “I couldn’t get my combos going. He’s extremely fast and a very tough opponent.”

Pettis had been out of action since he won his belt in August 2013 with a first-round submission victory over Benson Henderson. After recovering from knee injuries and surgery, Pettis spent several weeks of the summer taping the new season of “The Ultimate Fighter,” coaching the UFC’s new women’s strawweights opposite Melendez.

Pettis’ title capped a steady rise for the athletic tactician from famed trainer Duke Roufus’ Wisconsin gyms. He rose to prominence with his famed “Showtime” kick in December 2010, leaping off the cage wall to land a jaw-dropping head kick on Henderson.

Pettis had fought just three times in the previous three years, winning all three bouts in the first round and raising worries of ring rust.

Yet Melendez also hadn’t fought in 14 months since his bloody victory over Diego Sanchez in one of 2013’s best bouts. Melendez, the veteran former Strikeforce champion from San Francisco, had a UFC title shot in April 2013, but lost a razor-thin decision to Henderson.