Jalen Williams erupted for 40 points as the Oklahoma City Thunder held off the Indiana Pacers to score a 120-109 victory and move to within one win of clinching the NBA Finals on Monday.

An enthralling Game 5 battle in Oklahoma saw the Pacers climb out of an 18-point first-half hole to get within two points of the Thunder in the fourth quarter.

But, just as Indiana threatened to make the latest in a series of trademark comebacks, the Thunder found an extra gear with Williams and NBA Most Valuable Player Shai Gilgeous-Alexander steering the team to a pivotal victory.

The win leaves the Thunder 3-2 up in the best-of-seven series, meaning it can seal the NBA crown with victory in Game 6 in Indianapolis on Thursday.

Williams finished with 40 points, six rebounds and four assists, while Gilgeous-Alexander co-starred with 31 points and 10 assists, four blocks and two steals.

"My teammates instill a lot of confidence in me to go out and be me," Williams said. "And (coach) Mark (Daigneault) has done a good job of telling me to just be myself.

"I don't need to be anything more, and that's given me a lot of confidence."

Williams said Oklahoma City's experience in Game 1 — when it blew a 15-point fourth-quarter lead to lose — had helped it close out victory.

"Tonight was the exact same game as Game 1, to be honest," Williams said. "Learning through these finals is what makes this team good, and we were able to do that."

Pascal Siakam led the Indiana charge with 28 points, but the Pacers were left sweating on the health of star point guard Tyrese Haliburton after the loss.

Injury woes

Haliburton, whose fitness has been under a cloud since Game 2 of the series, left the game in the first quarter with a right calf problem before returning later in the contest.

The Pacers talisman finished with just four points from a bitterly disappointing outing — all of them coming from free throws — as the Thunder's vaunted defense clamped down on the Pacers.

"He's not 100 percent, it's pretty clear," Pacers head coach Rick Carlisle said. "But, I don't think he's going to miss the next game.

"We were concerned at halftime, and he insisted on playing, but he's not 100 percent. There's a lot of guys in the series that aren't."

Haliburton discussed sitting out the remainder of the game with head coach Carlisle at halftime, but eventually returned after the break.

"It's the Finals, man. I've worked my whole life to be here and I want to be out there to compete, help my teammates any way I can," Haliburton said.

"I was not great tonight by any means, but it's not really a thought of mine to not play here. If I can walk, then I want to play.

"It is what it is. Got to be ready to go for Game 6."

Haliburton said the Pacers would only be thinking about winning Game 6.

"The thought is, if you lose, the season is over. So our backs are against the wall," Haliburton said.

"We've got to take this a day at a time. Our backs are against the wall. You have to look at Game 6 like it's a Game 7.

"We've got to go in and take care of business, just approach the game the right way."

His teammate Siakam backed Haliburton to fight through the pain barrier.

"He's a fighter. He's been our rock all year," Siakam said of Haliburton.

"He's a big reason why we're here. I don't know exactly what's wrong, but I know he's fighting, and he's going to give us everything he's got.

"We are a hundred percent behind him."

Oklahoma asserted control early in the first quarter, stretching into a 29-17 lead after Cason Wallace drained his first three-pointer of the playoffs.

With Chet Holmgren leading an inspired Thunder defensive display, the Pacers offense struggled to make any impression.

At the other end, Williams and Gilgeous-Alexander began to impose themselves, combining for 29 points in the first half.

Sensing an opportunity to build a commanding lead, Oklahoma City kept the points flowing, and two Gilgeous-Alexander free throws pushed the lead to 18 points before Indiana cut it to 59-45 at halftime.

With Haliburton a pale imitation of his usual self, another Thunder blowout looked on the cards.

But, the Pacers improved the speed of their ball movement, and an eye-catching bench cameo from Haliburton's back-up, TJ McConnell, suddenly turned the tide.

The Pacers outscored the Thunder 34-28 in the third quarter to trail by just eight points heading into the final frame.

A Siakam three-pointer with just over eight minutes left made it a two-point game at 95-93, as tension engulfed the crowd at the Thunder's home court in the Paycom Center.

But that was as close as the Pacers would get, and with Williams and Gilgeous-Alexander combining for 20 fourth-quarter points, the Thunder pulled away to power home.

AFP