Pascal Siakam scored 21 points to lead seven Pacers players in double figures as Indiana pushed Eastern Conference top seeds Cleveland to the brink of elimination in their best-of-seven conference semi-final.

There were no such offensive fireworks in Denver, where Oklahoma City squelched the Nuggets' second-half comeback bid to claim a gritty 92-87 victory in a game where both teams struggled to get shots to fall.

In Cleveland, the Pacers already had the game well in hand, with an 80-39 halftime lead, when the Cavs announced that star Donovan Mitchell was doubtful to return for the second half with a left ankle injury.

Mitchell, coming off back-to-back 40-point games, scored 12 points in the first half, but was clearly hurting when he tested his ankle prior to the start of the second half.

His loss would be a body blow for a Cleveland team hoping to fend off elimination when they host game five on Tuesday.

Coach Kenny Atkinson said Mitchell would have an MRI scan on Monday and he had "no idea" if Mitchell would be available for game five.

Despite the Pacers' dominance, there was no shortage of emotion.

Indiana reserve Bennedict Mathurin was ejected with 4:32 left in the first quarter for a punch to De'Andre Hunter's chest.

Hunter received a technical foul for responding with a two-handed shove that sent Mathurin sprawling, while Indiana's Myles Turner got a technical for wading into the fray.

Up 38-23 after one quarter, the Pacers piled it on in the second period, a 17-0 scoring run pushing their lead to 78-37 on the way to an 80-39 halftime lead.

Cleveland made just eight baskets in the first half while the Pacers put on an offensive display.

A Turner basket at the rim, off a no-look pass from Tyrese Haliburton, sent the Gainbridge Fieldhouse crowd into a frenzy.

The Pacers were also on-target from deep, making 12 of their 15 three-pointers in the first half.

"This is a group that plays better through adversity," Turner said of the Pacers' rebound from their game-three defeat.

"We got punched in the mouth last game, we had a hell of a response. The starters set the tone and the bench picked it up the rest of the game."

Turner and Obi Toppin added 20 points each for Indiana and Haliburton finished with 11. Darius Garland led Cleveland's scoring with 21 points, but the Cavaliers gave up 22 turnovers leading to 35 Pacers points.

- Tired legs -

In Denver, Shai Gilgeous-Alexander scored 25 points with six rebounds and six assists to lead Oklahoma City, but the Thunder connected on just 31 of 87 shots from the field -- only marginally better than the Nuggets' 25-for-80 success rate.

NBA Most Valuable Player Nikola Jokic scored 27 points and grabbed 13 rebounds for Denver, who shook off a dismal start and grabbed a 53-52 lead midway through the third quarter on a three-pointer from Aaron Gordon.

Jamal Murray and Christian Braun scored 17 points each and Gordon added 15 as Denver extended the lead to eight points early in the fourth.

But less than 48 hours after a draining overtime triumph Friday in game three, the Nuggets failed to capitalize.

Oklahoma City regained the lead on Cason Wallace's three-pointer with 8:35 to play and held on until the end.

"We got stops, held them to 18 points in the fourth quarter," Gilgeous-Alexander said. "They obviously came out hot after halftime, jumped on us, but defensive end is always it for us... We got it back on track and we were able to get a W."

Having avoided falling into a 3-1 hole, the Thunder host game five on Tuesday.

"I thought tired legs out there from both teams," Nuggets coach David Adelman said. "Give their team credit, in a really disgusting basketball game, those guys made plays, made enough plays to push them over the edge and win the game."