And, right when they needed him most.
"I just happened to be in the right place at the right time," Pierce said. "I saw him split the defenders, I saw him go up, I went up with him.
"I got my hand on the ball -- game over."
The Nets will begin the conference semifinals at Miami on Tuesday night, facing the two-time defending NBA champion Heat.
Pierce had more fouls (three) than points (none) in the second half, but his only block of the game punctuated a hard-fought series win for the Nets.
Leading by one, Brooklyn used its final timeout after failing to inbound the ball. On the second opportunity, Shaun Livingston tried a lob pass to Pierce, but Terrence Ross got a hand on the ball and then knocked it off Pierce and out of bounds for a turnover.
"I rushed it a little bit," Livingston said. "I'm thinking Paul is going to hold him off. He kind of slipped there. Once he slipped, it was a jump ball and Terrence Ross is probably the last guy you want to throw a jump ball to."
Toronto used a timeout and gave the ball to Lowry, whose driving shot was blocked by Pierce as time expired. Lowry lay prone in the key as the Nets surged onto the court in celebration.
"I really didn't have a great offensive game," Pierce said. "I was in foul trouble for most of the night. Sometimes you've got to find ways to help your ballclub win."
Nets coach Jason Kidd said Brooklyn's defense "bent a little" but didn't break, thanks mostly to Pierce's clutch play.
"Paul said it best, that's why he's here, to make plays," Kidd said. "He didn't have a great game, but it only takes one play to help a team win and that's what he did tonight."
Brooklyn went 4-0 against Miami in the regular season, but that didn't mean much to Brooklyn's Kevin Garnett.
"That goes out the window," he said. "This is the postseason. They're playing very well. They went right through Charlotte without a beat and they have a lot of confidence."
Joe Johnson scored 13 of his 26 points in the fourth quarter to lead the Nets. Marcus Thornton scored 17, Garnett had 12 points and 11 rebounds for his first double-double of the series, and Deron Williams added 13 points.
"Joe has kept us alive this whole series," Garnett said.
Amir Johnson fouled out with 20 points and 10 rebounds for Toronto, which trailed by 10 with just over six minutes remaining before storming back and having a chance to win it at the buzzer.
"They pushed us to the brink," Livingston said.
Lowry finished with 28 points and DeMar DeRozan 18 for the Raptors, who fell to 0-2 in franchise history when playing in a Game 7. Toronto lost Game 7 of the conference semifinals to Philadelphia in 2001.
"We were right there," said a rueful Raptors coach Dwane Casey.
The Raptors, who won the Atlantic Division and set a franchise record with 48 wins, have not won a playoff series since 2001, losing in all three appearances.
Brooklyn led 81-73 to begin the fourth quarter, but Toronto cut the deficit to five at 90-85 on a layup by Lowry with 7:21 left.
Joe Johnson hit a driving hook shot on the next possession, then followed with a 3, putting the Nets up 95-85 with 6:18 remaining.
Patrick Patterson, who missed two key free throws late in Toronto's Game 3 loss, hit a pair from the line with 56 seconds left, bringing the Raptors to within four at 101-97. Patterson finished with 16 points.
After a missed shot by Pierce, Lowry was fouled and made both free throws, making it 101-99 with 25 seconds remaining.
Trying to force a steal, Lowry fouled Williams on the inbound pass. Williams missed the first but made the second, putting the Nets up three at 102-99. After Toronto called a timeout, Lowry drove for a layup to cut it to one at 102-101 with 16 seconds to go.
Toronto put Livingston at the foul line and he made both shots, restoring the Nets' three-point lead, but Ross drove for a layup to cut it to one again with 8 seconds left -- setting up the frantic finish.
"We battled," Amir Johnson said. "We just ran out of time."
He picked up his fourth and fifth fouls early in the third quarter and Brooklyn led 67-55, its biggest lead of the game, after a pair of free throws by Williams at 9:04.
But Toronto went on an 8-2 run as the Nets missed eight straight shots before Andray Blatche ended the drought with a dunk. Alan Anderson made a jumper and Blatche added a layup, restoring Brooklyn's 12-point edge. DeRozan hit a buzzer-beating 3 to cut it to 81-73 heading to the fourth.
NOTES: The Nets outrebounded the Raptors 42-38. ... Garnett's double-double was his 86th in the playoffs, second only to San Antonio's Tim Duncan. ... Former Raptor Charles Oakley attended the game, as did Maple Leafs captain Dion Phaneuf and his wife, actress Elisha Cuthbert. ... After he got stuck in traffic on his way to the game, Casey turned around and drove home, then took the subway to the arena. Several major downtown streets were closed Sunday because of the Toronto Marathon. ... The Raptors dropped to 3-8 in games that begin before 6 p.m. ... The team that led at halftime won all seven games.