Lowry scored a career playoff-high 36 points, including the go-ahead 3-pointer after Toronto had blown a 26-point lead, and the Raptors beat the Brooklyn Nets 115-113 to take a 3-2 lead in their first-round series.
''He was definitely carrying them in the first half,'' Nets guard Deron Williams said. ''He's just tough to guard when he gets like that. He's got a lot of confidence right now.''
Joe Johnson scored 30 points and Mirza Teletovic had 17 for the Nets, who scored 44 points in the fourth quarter but lost their final chance when Andray Blatche fired a pass well over Deron Williams' head into the backcourt for a turnover.
Blatche said Lowry's defensive pressure on the play led to the decisive mistake.
''Shaun (Livingston) made a great play to keep the ball alive,'' Blatche said. ''I tried to get the ball out to (Williams) so he could get the 3 and take the game home. (Lowry) ran out and was forcing me to make a tougher pass and I threw it in the backcourt.''
Nets coach Jason Kidd said Lowry is someone who is ''never going to stop playing.''
''Tonight he made some big shots plays and made some big shots down the stretch,'' Kidd said.
DeMar DeRozan had 23 points, Jonas Valanciunas scored 16 and Greivis Vasquez added 15 for the Raptors, who would advance to face Miami in the second round with a victory in Game 6 on Friday in Brooklyn.
The Nets, meanwhile, are facing elimination after consecutive losses.
''We've just got to play with a sense of urgency,'' Williams said. ''We have to now. If we lose, we're done.''
Game 7, if necessary, would be Sunday in Toronto.
''I think we'll play better on Friday at home and we'll see them back here Sunday,'' Nets forward Paul Pierce said.
Toronto led 94-72 on a 3-pointer by Vasquez with 11:23 remaining, but Brooklyn scored 15 of the next 18 points, including a four-point play by Alan Anderson, to make it 97-87 with 7:15 remaining.
''Every mistake you could think about, we made in the fourth quarter,'' Raptors coach Dwane Casey said.
Johnson later converted a three-point play, then made a 3 to tie it at 101 with 3:16 left.
Lowry put Toronto back on top with a pair of free throws, and a 3 by Vasquez gave the Raptors a five-point lead with 2:46 left.
Two free throws by Blatche and a 3 by Teletovic tied it at 106 with 1:23 left, but Lowry made a 3, then followed a layup by Blatche with a driving hook shot, putting the Raptors up 111-108 with 27 seconds remaining.
Johnson missed a jumper and DeRozan was fouled after grabbing the rebound, making both to put Toronto up by five, but Amir Johnson fouled out on Anderson's corner 3. Anderson's free throw made it 113-112 with less than 10 seconds left.
''They got stagnant and kind of got tight'' Livingston said. ''We were playing a little bit loose and free.''
DeRozan, who finished 12 of 13 at the line, added two more free throws to give Toronto a 115-112 lead with 6 seconds left. After a timeout, Blatche was fouled and made the first free throw but missed the second. Blatche grabbed the rebound and tried to pass it to Williams but the ball sailed into the backcourt for a turnover, sealing victory for Toronto.
Brooklyn led 23-18 on a 3 by Anderson with just over two minutes left in the first, but the Raptors reeled off seven straight points, including a 3 by Lowry, to take the lead. Lowry hit another 3 before the quarter ended and Amir Johnson scored nine points in the first as Toronto led 28-25 after one.
The Raptors used another huge surge to widen their lead in the second quarter. A three-point play by Marcus Thornton put the Nets up 40-36 with 5:26 left in the half, but Lowry scored five points in a 13-0 run to give Toronto a 49-40 lead, causing the Nets to call timeout.
Pierce stopped the run with a driving basket, but the Raptors scored the final eight points of the half, including a buzzer-beating 3 by Lowry that went in off the glass. Toronto led 62-44 at halftime, setting a playoff record for points in a half.
Joe Johnson scored 18 points in the third for Brooklyn, but the Raptors pulled further away thanks to eight points from Valanciunas and seven by Lowry, taking a 91-69 edge into the fourth.
NOTES: The Raptors scored 61 points in the first half of Game 3 in their first round series against Orlando on Apr. 24, 2008. ... Rapper 50 Cent attended the game, as did former Raptors player Morris Peterson.