NEW YORK -- Canelo Alvarez kicked off the richest athlete contract in sports by doing just what was expected on Saturday night at sold-out Madison Square Garden.

Heavy favorite Alvarez, the unified middleweight world champion and boxing's biggest star, moved up one weight class and destroyed the game Rocky Fielding with a heavy body attack to take his secondary super middleweight world title by third-round knockout in his first non-pay-per-view fight since 2015.

Alvarez knocked Fielding down four times, much to the delight of the raucous pro-Canelo crowd of 20,112.

Canelo Alvarez, right, floored Rocky Fielding four times, including twice in Round 3, when the fight was stopped. Ed Mulholland/Matchroom Boxing USA

The fight was Alvarez's first in New York, a place he had always wanted to fight, and it represented the first bout of the record-breaking contract he signed in October with new sports streaming service DAZN. Looking for a franchise athlete, DAZN lavished Alvarez with a five-year, 11-fight, $365 million deal to take him off pay-per-view in hopes that he would help drive subscriptions to the $9.99-per-month service.

Alvarez had been under exclusive contract to HBO and was the biggest pay-per-view star of the post-Floyd Mayweather era, but that contract expired in September, and HBO made no move to retain his services because it decided to dump boxing coverage, which it concluded last week after 45 years of covering the sport at the highest level.

Alvarez (51-1-2, 35 KOs), 28, of Mexico, moved seamlessly to his new outlet and shined in his debut against an overmatched opponent in Fielding, whom virtually nobody gave a chance to win or even compete.

The fight was as big of a mismatch as most expected, and Alvarez tortured Fielding to the body.

"That was the plan in the gym, to hit the body and then move up [to the head], and that's the result. You see the result here," Alvarez said through an interpreter.

Final punch stats Fighter Total Jabs Power Alvarez 73 of 141 (52%) 6 of 38 (16%) 67 of 103 (65%) Fielding 37 of 183 (20%) 4 of 36 (11%) 33 of 147 (22%) -- Courtesy of CompuBox

Alvarez was coming off the biggest win of his career in September, when he narrowly outpointed Gennady Golovkin to win the unified middleweight world championship in the biggest fight of the year, a rematch of last year's controversial draw. Alvarez wanted to fight once more this year after a failed drug test cost him the GGG rematch in May because of a suspension.

He took the opportunity to cherry-pick a titleholder at 168 pounds in Fielding and won a belt in his third weight division, despite the title being a second-tier version.

Fielding (27-2, 15 KOs), 31, of England, was making the first defense of the belt he won in July, when he upset Tyron Zeuge by fifth-round knockout on his turf in Germany in July. But Alvarez is no Zeuge, and it showed immediately.

Alvarez came out fast in the first round, banging the much taller Fielding's body and throwing hooks to the head. Fielding, who had a far longer reach, tried to get his jab going, but it was no use. Alvarez hammered him with a left hook to the liver, and Fielding went down to a knee.

Fielding beat the count but took a beating the rest of the round, as Alvarez landed many more body shots and a left uppercut.

Alvarez continued the assault in the second round, forcing Fielding backward with an assortment of power punches; but Fielding landed a few of his own, though Alvarez did not seem at all bothered by the blows. Late in the second round, Alvarez landed a left hook to the liver, a carbon copy of the shot he executed in the first round, and Fielding went down again.

It seemed like every shot Alvarez landed in the third round buckled Fielding, who kept trying and threw punches back. But Fielding was fading fast, and with about 40 seconds left, Alvarez landed a right hand to the head to knock him down for the third time. Fielding again beat the count, but moments later, Alvarez landed yet another crushing left hook to the body. Fielding took a step back, winced and went down to a knee, and referee Ricky Gonzalez waved off the fight without a count at 2 minutes, 38 seconds.

"Canelo is an elite fighter, and I never shied away from a challenge," Fielding said. "It was a great week, met some great people. I lived a dream. Hats off to Canelo. I respect him."

Alvarez's body attack was something to behold. With Mexico's most famous body puncher, Julio Cesar Chavez Sr., working ringside on the Mexican television broadcast, Alvarez surely made him proud. According to CompuBox punch statistics, Alvarez landed 73 of 141 punches (52 percent), including 35 to Fielding's body. Fielding landed 37 of 183 punches (20 percent).

"He's strong. I was catching some shots, but he kept coming forward," Fielding said. "The body shots were really tough. He placed his shots well, and he caught me. I stood there too long and tried to mix with him. I gave it everything, and the better man won."

Alvarez weighed 167.4 pounds, the heaviest of his career, and he looked powerful at the weight.

"Very good, very strong," Alvarez said of how he felt at the new weight. "I didn't have to dehydrate myself to make weight. I feel good, and I feel strong."

All along, Alvarez said his foray to super middleweight was a one-shot deal. He was doing it, he said, only because he wanted to become one of the few Mexican fighters to win a world title in three weight divisions.

His next fight is scheduled to be May 4 at T-Mobile Arena in Las Vegas. Alvarez was not as committed to a return to 160 pounds for that fight to defend the middleweight title as he had been in the buildup to the fight with Fielding.

"We'll have to see," Alvarez said when asked which division he would box in next. "I have to talk to my team, enjoy the holiday, and then I'll talk to my team. But right now, without a doubt, what I want are the best fights. What I always want to do is to make the best fight, whether they're for world titles or not. Right now, what I can tell you is that I just want to make the best fights for the public."

Golden Boy Promotions CEO Oscar De La Hoya echoed Alvarez's thoughts because he was impressed with how strong Alvarez looked at super middleweight.

"It showed he can either fight at 160 or 168," De La Hoya said. "We have no opponent whatsoever. We're not even thinking of nobody. We are going to enjoy the holidays, enjoy our families, and then as a team we will choose who Canelo will fight, whether it is at 160 or 168. He has many choices as we speak."

The most attractive fights are certainly in the middleweight division, in which Alvarez could face GGG in a third fight, though Golovkin remains a broadcast free agent and is in the process of weighing offers from ESPN, DAZN and Premier Boxing Champions, which has deals with Showtime and Fox.

"For me, I feel like on Sept. 15, I showed that I was best, but it was two great fights [with Golovkin], and if the people want it, we can make it," Alvarez said.

There also is titleholder Daniel Jacobs, who was ringside and has been campaigning for a fight after claiming a title on Oct. 27. Jacobs also is a broadcast free agent, but he appears headed toward renewing his promotional deal with Matchroom Boxing promoter Eddie Hearn, who has a deal with DAZN.

Alvarez said that regardless of whom he fights, in whichever division, he will not shy away from quality opposition, Saturday's mismatch notwithstanding.

"My goal is to make good fights for the people, for the public and to make sure the name of Canelo Alvarez and of Mexico is held up high," he said.