MIAMI — Dwyane Wade isn't ready for the offseason. Not even close.

And thanks to another record-setting effort by their star, the Miami Heat suddenly have life in their series against the Boston Celtics.

Undeterred by talk that this might have been his final home game in Miami, Wade set franchise playoff records by scoring 46 points, 30 in the second half, and the Heat kept their season alive by beating the Celtics 101-92 on Sunday in Game 4 of their Eastern Conference first-round series.

"We don't take Dwyane for granted, that greatness," Heat coach Erik Spoelstra said. "We don't. He has another gear, another depth to go into in his soul to be able to dig it out and really carry a team on his back with his will. ... When his back is against the wall, it's an utter defiance."

The Celtics still lead 3-1, and get a second shot at the clincher on Tuesday in Boston.

But Wade gave the Heat hope.

"You better believe this group is inspired," Spoelstra said.

Quentin Richardson scored 20 points and Michael Beasley added 15 for the Heat, who wasted an 18-point first-half lead before digging deep to extend the season.

Rajon Rondo led the Celtics with 23 points. Kevin Garnett had 18 points and 12 rebounds, Paul Pierce scored 16 and Ray Allen added 15 for Boston, which was bidding for its first 4-0 sweep of a series since 1986.

Not so fast.

Wade scored 19 points in the final quarter alone. He'll opt to become a free agent after the season, and on the slim chance that this was his final home game in Miami, it was nothing short of scintillating.

Trailing by six entering the final quarter and needing a rally to keep the season alive, Miami opened the fourth on a 25-8 run, fueled mostly by Wade. He hit a pair of 3-pointers about a minute apart, stopping after the second to scream at his right hand, giving Miami an 85-80 lead.

"Just a sensational player," Celtics coach Doc Rivers marveled.

Another 3-pointer from Wade made it 93-82 with 6:12 left.

Over, right?

Not against the Celtics.

Boston was 6-0 against Miami this season, and had won 14 of the last 15 between the clubs since April 2007. So of course the Celtics would make a run — getting within 96-92 on a free throw by Allen with 2:36 left.

Then a funny thing happened. Not only did Allen — a 91 percent foul shooter this season — miss the second, he missed two more with 1:50 left, keeping it a two-possession game.

And when Dorell Wright missed a jumper with 1:50 left, Beasley swooped in, got the rebound and scored, making it 98-92.

Exhale, Miami. The season will go until at least Tuesday.

"I would love Ray to be on the line in Game 5," Rivers said.

Predictably, the Heat came out inspired.

Garnett scored the opening basket, only to have Miami reel off the next 12 points. Richardson made his first four shots, three of them from 3-point range, staking Miami to a 15-5 lead.

Wade scored 14 in the first, Richardson ended up with 13, and the Heat seemed well on their way, up 31-14 late in the opening quarter.

That duo combined for two in the second quarter, though, and Boston began chipping away.

Thanks in large part to Glen Davis tripping over his own feet and tumbling to the court in a green heap, Beasley had an alley-oop dunk with 8 minutes left until halftime, putting Miami up 42-24.

The rest of the half was all Boston, which quickly turned the arena mood from celebratory to concerned. The Celtics outscored Miami 19-7 to close the second quarter, with the Heat making six turnovers and missing eight of their next nine shots after the Beasley dunk, and the lead was down to only 49-43 at the break.

In the third, Wade did the spectacular. Boston did the steady, which worked better.

Wade drove past Allen down the middle of the lane, dunked over the outstretched arm of Garnett and walked into the second row of seats, tying the game at 64 as the crowd roared.

But Garnett, Pierce, Allen and Rondo all had big baskets late in the third, and the Celtics took a 77-71 edge into the final 12 minutes.

But the fourth, thanks to Wade, was all Miami.

Each Heat player had a sheet of paper at his locker when he arrived Sunday, the words "Easy vs. Hard" typed across the top.

"Making everyone go to Boston," the sheet said, "is hard."

And it was. But not impossible.

Getting the Celtics to fly back to Miami will be even tougher.