J.R. Smith had 22 points for New York, still short-handed in the frontcourt but looking much better with Anthony back. The NBA's second-leading scorer hadn't played since leaving the Knicks' road trip last week to have fluid drained from the back of his right knee.
He said he felt much better after the morning shootaround and moved much better, shooting 7 of 14 and grabbing eight rebounds.
The Knicks shot 53 percent and won their second straight after dropping the first four games of their five-game trip. All-Star center Tyson Chandler is expected to miss about a week with a bulging disk, and reserve forwards Amare Stoudemire, Rasheed Wallace and Kurt Thomas all could miss the rest of the regular season. But New York had no trouble despite using a small lineup that featured 6-foot-9 Kenyon Martin as the center.
Iman Shumpert, who joined Anthony, Martin, Raymond Felton and Pablo Prigioni in the lineup, sat out the second half after hurting his knee late in the first half. He sat on the bench in uniform and the team said he was available to play, but wasn't needed once the Knicks blew it open.
Tobias Harris and Andrew Nicholson each scored 14 points for the Magic in their fifth straight loss. They played without center Nikola Vucevic because of an illness in the second night of a difficult back-to-back, after falling by 22 at Indiana on Tuesday.
New York beat Orlando for the sixth straight time and swept the season series for the first time since 1997-98.
Anthony had sat out six of the previous eight games. He fell to the court without contact while trying to catch a pass in Cleveland on March 4 and missed the next three games. He returned but was clearly limited in losses at Golden State and Denver, and he finally realized the knee needed more than just rest.
He had rejoined the team on the West Coast following the procedure but didn't want to rush back, and determined he was ready Wednesday after feeling good over the last couple of days.
Anthony made a 3-pointer on the Knicks' first possession, and New York built a 22-7 lead after consecutive 3-pointers by Smith and Chris Copeland capped a 10-0 run. They led 26-15 after one, but Orlando got untracked with a 31-point second quarter, cutting it to 51-46 at the half.
The Knicks put it away midway through the third, getting two free throws and a follow shot by Anthony to start a 10-2 burst that extended a 10-point lead to 78-60.