However, Walker had one more shot. With center Al Jefferson setting a screen and forward Josh McRoberts making the outlet pass, Walker hit an 18-foot fade-away jumper to give the Hornets a 104-102 victory.
Walker finished with 29 points.
"I guess there was a little confusion on the defensive end, and I just found myself pretty open," Walker said. "Josh made a great pass to me, and I had a second, so I had a chance to turn around and set my feet and got a good shot up."
"I wanted the basketball," Walker said of his thought process in the closing moments. "I wanted to make that shot. I was happy to have the opportunity."
Lowry said, "It was a great play. It worked out well, really well for them. We have to make the home court more of an advantage for us."
Bobcats coach Steve Clifford added, "It was a good screen by Jefferson. A great pass by Josh. And then obviously Kemba, which is his nature, drilled the big shot. We were down double digits.
"The guys that were in there really battled hard, so it's really a good team win."
Center Jonas Valanciunas and forward Amir Johnson scored 10 each for TORONTO, and Johnson added 13 rebounds before fouling out in overtime. Guard/forward John Salmons scored 11 off the bench for the Raptors, who had a two-game winning streak end. The Bobcats won their second in a row.
"This one really hurt," DeRozan said. "We've got to get over it, come in tomorrow, watch film and correct mistakes."
The Bobcats held a three-point lead after Walker made two free throws with 27 seconds left in overtime. DeRozan scored on a layup with 12 seconds left, and then -- after Walker missed two free throws -- DeRozan hit one of two foul shots to tie the score at 102-102 with one second left, setting up Walker's buzzer-beater.
"Charlotte's a good team, they're better than people give them credit for," Raptors coach Dwane Casey. "Jefferson is handful down low, and Kemba Walker is a handful out front. We had to trap and double-team those guys, and that causes problems. That wasn't our 'A' game that we brought tonight -- in spots."
The teams entered the fourth quarter tied, but a 3-pointer by Lowry put the Raptors up by five. Henderson hit a pull-up jumper to cut the lead to one, and the Bobcats took an 82-81 lead on a layup by Sessions.
The Raptors regained the lead on a 3-pointer by Lowry. DeRozan banked in a shot with 5:47 to play for an 86-82 TORONTO lead. Jefferson tied the game with turnaround jumper with 3:46 to play. Charlotte took a one-point lead when Sessions made one of two free throws. Jefferson made a jumper with 2:31 to play, and the Bobcats led by three points.
"We knew what we had to do," Jefferson said. "We knew what we weren't doing, and we knew what it was going to take to win it."
NOTES: F Chuck Hayes was in uniform for the first time as a Raptor after completing baseline cardiac tests. He was one of four players acquired last week in a trade that sent three players, including F Rudy Gay, to the Sacramento Kings. ... Charlotte F Michael Kidd-Gilchrist (left hand fracture) missed his seventh consecutive game. He will stay in a cast until Dec. 27, when he will be re-evaluated. ... After a slow start to the season, Bobcats G Kemba Walker averaged 20.4 points in eight games leading into Wednesday. He scored 24 in a 95-87 win over Sacramento on Tuesday. ... The Raptors will play five of their next six games on the road, starting Friday against the Mavericks in Dallas. ... The Bobcats visit the Detroit Pistons on Friday before playing the Utah Jazz on Saturday in the opener of a three-game homestand.