Teofimo Lopez was brash enough to challenge Vasiliy Lomachenko, and good enough to beat him.

Lopez dominated early and finished strong Saturday night to win a unanimous 12-round decision over Lomachenko to unify the lightweight titles in a fight he demanded even though some thought he wasn't experienced enough.

Lopez took advantage of a slow start by Lomachenko to build up an early lead, then finished the fight with a big 12th round that left Lomachenko bloodied and beaten on the scorecards. The 23-year-old from Brooklyn became the unified lightweight champion and managed to do what few in boxing thought he could do – outbox perhaps the best technician in boxing.

Lopez (16-0) added the three titles held by Lomachenko (15-2) to the belt he won last year to become the undisputed 135-champion.

Lopez was favored 119-109, 117-111 and 116-112 on ringside scorecards in a bout held without fans at the MGM Grand conference center. The Associated Press had Lopez winning 117-111.

Lopez proved faster and stronger than the 32-year-old Lomachenko, who won two Olympic gold medals as an amateur and was regarded as one of the top pound-for-pound fighters as a pro. Surprisingly enough, he was also the better boxer and proved he could close the show by bloodying Lomachenko's eye in the 12th round.

"I had to dig deep, man," Lopez said. "I'm a fighter, I've got to dig in deep."

Lomachenko, ordinarily a slow starter, was too slow this time as he gave away rounds early as he tried to figure out the style of Lopez. By the time the fight got competitive in the eighth round he was too far behind to come back.

"He's been in a 14-month layoff," Lopez said. "I knew it was going to take him a long time to catch up."

Lomachenko, who lost only once in nearly 400 amateur fights and had only one loss as a pro, thought he did better than the scorecards indicated.

"Definitely I am not agreeing with the scorecards," he said.

The fight was the biggest since the pandemic began and would have been a pay-per-view event in normal times. But with no fans it was televised on ESPN, providing boxing with a bigger showcase than it would have gotten otherwise.

Lomachenko was a 4-1 favorite but looked rusty early as he tried to solve the style of Lopez. He threw punches only sparingly the first half of the fight, landing just 31 punches in the first seven rounds, before finally picking up the pace in the eighth round.

"I think the first half of the fight he got more rounds than I did but in the second half of the fight I took over," Lomachenko said. "I was much better."

Punch statistics showed Lopez landed 183 of 659 punches while Lomachenko was credited with 141 of 321. In the 12th round Lopez outlanded Lomachenko 50 to 19 and opened up a cut that sent blood flowing down his face and prompted referee Russell Mora to stop the fight with 10 seconds left to have the ring doctor look at it before resuming.

Lopez was told by his father in the corner before the 12th round that he was ahead and not to risk anything. But he came out strong and beat Lomachenko to the punch.

"I didn't know if they had him up on the scorecards or not," Lopez said.

Lopez did his trademark backflip in the ring after the unanimous decision was announced.

Lopez became the youngest fighter to become a four-belt champion in only his second title fight. He had sought the fight against Lomachenko, angering the Ukrainian with his brash tactics.

"I love to fight and I can bang too," Lopez said. "That's what a true champion does, I go out there and find a way to win."