LeBron James had 29 points and 14 rebounds and Dwyane Wade finished with 25 points and seven assists as the Miami Heat beat Oklahoma City 91-85 to take a 2-1 series lead in the NBA finals.
Wade sank two free throws with 13 seconds remaining in the fourth quarter to cap the scoring for the Heat, who are in the finals for the second year in a row and trying to win their first championship since 2006.
"We had enough stops, enough timely scores and we were still able to get some free throws down the stretch to find a way to grind out a win," Miami coach Erik Spoelstra said.
James, the regular season NBA Most Valuable Player, made 11-of-23 shots from the field and was a force on both defence and offence. He finished just shy of posting his sixth consecutive playoff game of 30 or more points.
Miami, which will host the next two games in the series, can take a stranglehold on the Thunder with a victory in game four on Tuesday.
Chris Bosh had 10 points and 11 rebounds for the Heat, who scored their final five points from the free-throw line in front of a crowd of 20,003 at American Airlines Arena.
Miami shot 88 percent from the line compared to only 62 percent for the Thunder.
NBA scoring champion Kevin Durant had 25 points, Russell Westbrook scored 19 points and Kendrick Perkins had 10 for the Thunder, who got off to their best start of the series in the first quarter but couldn't execute down the stretch.
Durant got into foul trouble for the second game in a row and had to sit on the bench for a time in the third, which seemed to slow down the Thunder's attack.
Both teams made mistakes and turned the ball over in the fourth, but Miami had more composure at the end of the game.
"We missed free throws and we turned that ball over too many times in the fourth quarter," said Thunder coach Scott Brooks. "It was a very intense playoff game. I thought we gave ourselves a chance to win. Give them credit because they are a physical team and they made some plays down the stretch."
With just 16 seconds to play, and the Thunder trailing by four points, Oklahoma City's Thabo Sefolosha tried to hit Westbrook but turned the ball over with a bad inbounds pass, forcing the Thunder to foul Wade, who then made two free throws.
Heat forward Bosh said they are motivated by the memory of their loss to the Dallas Mavericks in last year's final.
"Everyday we remind ourselves," Bosh said. "We think of that pain that we experienced last year. It hurts a lot worse when you are not successful as opposed to your lungs burning and your muscles burning from giving that extra effort.
"We carry that pain with us."
The Thunder came out much better in the first quarter than they had in the opening two games. But they couldn't stop the Heat offence as Miami's big three of James, Wade and Bosh started clicking from the opening tip-off.
James scored 10 points in the first for the Heat, who zipped the ball around quickly on offence, making the Thunder defence look slow and flatfooted at times.
For the third straight game, the Heat also dominated in the paint in the first quarter by scoring 20 points compared to 12 for the Thunder.
But Oklahoma kept the score close all game thanks to Westbrook and Durant. Durant shot six-of-10 from the field and had 13 points in the first half while the sometimes erratic Westbrook had 13 points and didn't turn the ball over once.
Spoelstra said he was pleased with the way Miami didn't fold in the third quarter when the Thunder made a charge.
"This playoff run that we've been on, we've been knocked down to the canvas several times," Spoelstra said. "We got down by 10 tonight but our guys furrowed their brows and got back to grinding."
The teams traded three pointers to end the first half as Miami's Shane Battier nailed a three pointer just 20 seconds before Westbrook finished the scoring in the first half with a three-point shot that cut Miami's lead to 47-46.
Thunder guard Derek Fisher registered the first four-point play in the NBA finals in three years in the third quarter. The former Los Angeles Laker, who is in his 15th season, was fouled on a shot from beyond the arc then made the free throw with 4:33 left to give the Thunder a 10-point lead, 64-54.
But the Heat went on a 15-7 run in the final 5:41 of the third with Durant on the bench to take a 69-67 lead into the fourth.