Davis charged into the fans' seating area during a timeout in overtime to confront a fan he says he believed was "threatening" his wife, Kendra.
The incident cast a shadow on the Bulls' thrilling 106-104 victory, won with Ben Gordon's buzzer-beating 22-foot jump shot in the overtime.
Davis' action, for which he was ejected, is the first time an NBA player has gone into the stands since last season's brawl in Auburn Hills, Michigan, involving the Pistons, Indiana Pacers and fans that resulted in criminal charges and lengthy suspensions of players.
League-wide, Davis is one of the most respected players and is president of the National Basketball Players' Association. In a statement issued after the game, Davis said he believed an intoxicated fan was threatening his wife.
"I saw him touch her," he said. "I know I should not have acted the way I did, but I would have felt terrible if I did not react. There was no time to call security. It happened too quickly."
Neither the Bulls nor the league issued a statement after the game.
Knicks coach Larry Brown, who was the Pistons coach a year ago, said the two incidents are far different.
"Come on, that's his wife," Brown said. "That's entirely different. I was worried about Kendra. That's why he went in the stands, he saw her falling back.
"That thing that happened in the stands had nothing to do with the two teams. That's a man concerned about his family."
Davis' behavior was one of two peculiar incidents.
Earlier in the overtime, the Bulls' Chris Duhon almost came to blows with the Knicks' Maurice Taylor after Taylor fouled him hard.Duhon apparently was standing up for himself with the steely toughness Bulls general manager John Paxson had sought with stern words a day earlier. It came with a price for the scrappy 6-foot-1-inch captain who was ejected along with Taylor.
"I don't think that's exactly what (Paxson) was talking about," Duhon said. "I just felt that it was a cheap shot. He just bulldozed right over me, and I just reacted."
Bulls show some fight
Paxson didn't attend the game because he was on a scouting trip. Duhon's reaction stirred emotions for many of 21,268 fans who stuck around for the overtime. It certainly ignited the Bulls, who routinely have played without passion this season.
"I was glad to see us show a little fight," Skiles said.
Gordon had a spectacular night, at one point finagling past the Knicks' Jamal Crawford, Davis and Channing Frye for a stunning drive in the fourth quarter.
For only the second time this season, Gordon had a double-figure fourth quarter, scoring 13 of his season-high 32 points in the final 12 minutes of regulation. He made 14 of 28 shots.
"There were a lot of crazy things happening," Duhon said. "A lot of wacky plays. Thank God we were able to come out with a win."
The crowd jeered Curry during player introductions, and they did the same to Crawford, another former Bull traded in the summer of 2004. Only Davis received polite applause of the three.
The strange events made Curry's return an afterthought. He had an off night, but more important, he was able to walk off the floor unassisted after a scary collision with Gordon with 7 minutes left in the game. Curry came back for the overtime.
In 25 minutes, Curry made 5 of 11 shots and scored 11 points with four rebounds before fouling out in overtime. A matchup with good friend Tyson Chandler never really materialized. Chandler also fouled out in the extra session.
Nuggets 90, Cavaliers 89
At Denver, Carmelo Anthony and Earl Boykins scored 17 points apiece for Denver, and Cleveland's LeBron James missed a free throw with .6 seconds left.
In other NBA action: New Jersey 101, Philadelphia 90; Orlando 106, Washington 98; Indiana 98, Charlotte 92; Detroit 117, Atlanta 89; Boston 103, Minnesota 96; New Orleans 87, Memphis 79; Dallas 103, Houston 76; San Antonio 95, Milwaukee 92; Phoenix 112, LA Clippers 102; Portland 96, Toronto 94.