LeBron James' display for the Cleveland Cavaliers against the Boston Celtics earned fulsome praise from coach Tyronn Lue, who said "we needed him to be big, and he was big".

The Cavs came into Friday's meeting 3-2 down in the Eastern Conference Finals and staring elimination in the face, but James took centre stage in a 109-99 win at Quicken Loans Arena.

After Kevin Love left the game with a concussion, James finished with 46 points, adding 11 rebounds and nine assists as the Cavs forced a decider in Boston on Sunday.

Asked what he saw in James' stellar performance, Lue responded: "Greatness. Championship pedigree. Giving it his all. We needed that, especially when Kevin went down.

"We had to play Bron as many minutes as he had to. He delivered. He was up for the challenge. He carried us home as usual.

"But a lot of other guys stepped up, too. I thought Jeff Green did a great job. I thought [Jordan] Clarkson came in and gave us some good minutes. George Hill being aggressive. Larry Nance plays that whole fourth quarter. Guys really chipped in and helped in the absence of Kevin.

"And LeBron brought us home, as usual. Big shots, playing through being tired and fatigued. We needed him to be big, and he was big."

James did suffer a minor injury scare when he sustained a knock to the knee, but he showed few ill-effects in rattling in a further 12 points after that blow to put the seal on another game-winning display.

"I tried to get him to bang his other knee so then we could have 24," joked Lue.

"But no, he just fought through everything tonight. He was huge. That's what you expect out of the best player in the world. You expect games like this on elimination nights. I think he's the all-time leading scorer on elimination games, so add this to it."

On Love's injury, Lue was unable to provide an update with game seven less than 48 hours away.

"I have not had a chance to see the medical staff. I know at half-time they were evaluating him, but I don't know anything right now," Lue said.