Leo Santa Cruz and Abner Mares engaged in a scintillating, punch-filled featherweight match that had the crowd at the Staples Center in Los Angeles cheering wildly throughout the 12-round bout.
In the end, it was the more accurate Santa Cruz who won a unanimous decision by scores of 115-113, 116-112 and 117-111 to retain his featherweight title.
"It was a great fight -- another war," Santa Cruz said. "I had to be smarter. ... Abner is a great fighter. He left his heart out there."
The all-action bout was a rematch of their thrilling August 2015 bout at the same venue, which Santa Cruz won by majority decision.
At the sound of the opening bell, Santa Cruz and Mares picked up right where they left off the first time, standing toe-to-toe and exchanging punches at a rapid-fire pace. Mares edged the first and second rounds, making good use of his left hook on the inside, as Santa Cruz countered with solid punches of his own.
The 29-year-old Santa Cruz (35-1-1, 19 KOs) jabbed and countered effectively in the third, preventing Mares (31-3-1, 15 KOs) from closing the gap. It was a tactic that Santa Cruz, from Rosemead, California, put to good use for the remainder of the fight.
It was more of the same for the next four rounds, as Santa Cruz controlled the distance and connected frequently with jabs and a straight right to the head. Even so, the 32-year-old Mares, from Montebello, California, kept coming.
Mares finally got close enough to do some damage in the eighth, swarming forward to have his best round since the second. An accidental clash of heads opened a cut over Santa Cruz's left eye, but it never became a major factor.
"A cut is a cut," Santa Cruz said. "It's just blood. If anything, it brings more hunger out of me."
Mares continued to press forward and score in the ninth, but near the end of the round, Santa Cruz jarred him with two hard shots to the head.
The 10th was another close round with both boxers landing repeatedly, but Santa Cruz's punches were cleaner and appeared to have more snap.
The 11th was another give-and-take round. Santa Cruz scored well early, and Mares rallied late.
Sensing he was behind, Mares launched a final assault in the 12th round.
Santa Cruz stood his ground and they traded bursts of body shots. One flurry followed another and, as they did at the end of almost every round, the pair finished the fight standing chest-to-chest, banging away with everything they had.
According to CompuBox, Santa Cruz landed 357 of 1061 punches (34 percent); Mares landed 208 of 931 (22 percent).
"Without a doubt, Leo is the No. 1 featherweight in the world," Mares said. "I said before the fight that the winner of this would be the best in the world. I take my hat off to him."
Santa Cruz said he next wants a title unification fight with Gary Russell Jr., who also has a featherweight belt.
"Hopefully I am [the best featherweight in the world]," Santa Cruz said. "But I leave it to the fans to say who is the best. ... I want Gary Russell. Let's unify. I'm not scared of anybody."
The Associated Press contributed to this report.