"I didn't want to see the Celtics celebrating in my home floor with champagne and all that," said the Lakers' Paul Gasol.
"We didn't play our best game, but we played our hearts out."
Boston went on a 16-2 run midway through the final quarter to turn an 88-74 deficit into a 90-90 tie with just over four minutes left.
However Bryant stepped up and sealed the game with a big defensive play, poking the ball away from Boston's Paul Pierce as the Lakers clung on to a 97-95 lead with 40 seconds left.
Lakers forward Lamar Odom scooped it up and passed the ball down court to a streaking Bryant, whose jam pushed the lead to four points with 37 seconds left.
"He made a heck of a steal," Doc Rivers, Celtics coach, said.
"He made a really last ditch effort because Paul [Pierce] had him beat. He had no choice.
"He just came from behind and got a piece of the ball. Give him the credit."
Bryant hit only eight of 21 shots and had six turnovers but turned things around for his team when it mattered most.
|"We didn't play our best game, but we played our hearts out."|
"I had a bad game," Bryant, league MVP, said.
"You're not going to shoot the ball too well against this team because they're going to throw everybody at you.
"But the important thing for me is to push the buttons at the right time."
With Bryant struggling offensively, the Lakers had big games from Odom (20 points), Gasol (19 points, 13 rebounds), and Derek Fisher (15 points).
Pierce, who scored 38 points on 10 of 22 shooting from the floor and 16-of-19 from the free-throw line, said stopping Bryant was "the whole focus" defensively for the Celtics.
"He's a guy who can beat you all by himself, so the whole game plan is surrounding on stopping him and making other guys beat us," said Pierce.
"It's just unfortunate that we let the other guys beat us."