This will be the main event at the Hard Rock Hotel & Casino in Atlantic City.
Alvarez, who is based in Montreal, Canada, improves to 24-0 with 12 knockouts.
"I'm happy that we're working together because he has helped me a lot", Kovalev said in an interview with ESPN. Alvarez, a 2008 Olympian, nailed him with another left-right combination nearly immediately, and Fields jumped in to stop the fight. Plus, Alvarez enters the fight with a 3-inch reach advantage on the taller Kovalev.
"I feel OK. Thank you everyone, thank you very much to all the fans around the world for your support", Kovalev said. With blood streaming down his face, Alvarez continued to land power shot after power shot, eventually sending Kovalev to the floor for a second time.
"Sergey seems to gas out after six rounds", said Kathy Duva, Kovalev's promoter. "I saw a couple rounds in a couple of fights", he said.
"When you fight against the best guys like Kovalev, sometimes it makes you better because you're getting the experience". "That was a two-punch knockout". Alvarez, behind on all three cards, dropped Kovalev three times in the round before referee Harvey Dock stopped it at the 2:45 mark. But on Saturday, Kovalev found himself in the ring with a serious contender in Alvarez, who got the fight in April when original opponent Marcus Browne was dropped by Duva because of his arrest on a domestic violence charge. In the co-feature, rising star and WBA light heavyweight champion Dmitry Bivol (13-0, 11KOs) defends his belt against the crafty Isaac Chilemba (25-5-2, 10KOs).
It wasn't until the fourth round when Kovalev tried to exert his power, landing several hard punches that tested Alvarez's chin.
The Colombian Alvarez was the mandatory challenger for Adonis Stevenson's WBC light heavyweight belt for over two years but twice Stevenson paid Alvarez a step-aside fee in order to avoid him. But when that fight was delayed time and again, he quickly accepted the fight with Kovalev when it was surprisingly offered.
Alvarez stated, "I wanted to show him I'm strong, I have a good chin, and I'm ready for big things ... we practiced that punch during training camp, and that's how it went ..." If he tastes his punch it could be lights out so he has to fight the ideal fight to come home with the belt.
Despite Alvarez not being a big puncher, Kovalev knows that he's in for a tough fight.
This writer didn't catch the whole Bivol-Chilemba fight, but that matchmaking was worse, despite being defensible on a competitive level, because there was no way a spoiler like Chilemba was going to build any interest in Bivol's next fight, especially because Bivol is a conservative technician first who scores knockouts second.
He will win early rounds, and can nick a few in the middle stanza's, but down the stretch it will be Kovalev, driving forward with more vigour in his work, who takes command and ultimate walks away with a narrow but fair points win.