LAS VEGAS – Canelo Alvarez admitted that fatigue hindered him during the final few rounds of his 12-round win against Gennadiy Golovkin on Saturday night.

The 32-year-old Alvarez got off to a strong start and built a considerable lead on the scorecards, but Golovkin gave him some trouble once it was clear Alvarez grew tired by the ninth round. Golovkin was behind 78-74 on all three scorecards by then, which enabled Alvarez to secure a win that seemed more comfortable than the official scores submitted by judges Dave Moretti (116-112), David Sutherland (115-113) and Steve Weisfeld (115-113).

Alvarez explained during his post-fight press conference that his inability to train as hard as he wanted to prepare hurt his performance in the later rounds of their third fight at T-Mobile Arena.

“I think towards the end of the fight that I obviously started to get a bit fatigued,” said Alvarez, who retained his IBF, WBA, WBC and WBO super middleweight titles. “And that’s because we haven’t been able to work explosively in the gym. But this fight, with the problems that we had, I’m really happy with the performance tonight.”

Guadalajara’s Alvarez (58-2-2, 39 KOs) didn’t define exactly what he meant by working “explosively” in the gym, but he also revealed that his left wrist has hurt him since his 11th-round stoppage of Caleb Plant last November 6 at nearby MGM Grand Garden Arena. He’ll have surgery to repair cartilage damage in his wrist, which could keep him out of the ring until at least next May.

Alvarez said before he fought Golovkin for the third time, though, that his fragile knees allowed him to do roadwork for this training camp for the first time in more than four years. That should’ve enhanced his conditioning, but Alvarez, who has long dealt with stamina issues, was noticeably tired over the final four rounds.

The 40-year-old Golovkin threw 34 more punches overall than Alvarez, but he averaged only eight power punches through the first eight rounds, according to CompuBox’s unofficial statistics. Golovkin averaged 20 power shots over the final four rounds, yet still fewer than Alvarez, who landed almost twice as many power punches overall (85-of-217 to 46-of-171).

Golovkin (42-2-1, 37 KOs) connected on more jabs than Alvarez overall (74-of-350 to 45-of-270), but the Kazakhstan native appeared hesitant to throw right hands, particularly during the first half of their fight.

“What I feel, he didn’t throw his right hand because maybe he think I’m gonna counterpunch him,” Alvarez said. “Maybe that’s why he only throw the left hand. I just did my job. It was very difficult to hit him, too, because he’s like protecting everything, you know? It’s very difficult.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.