The defending National Basketball Association champions, who shot 71 percent in the second half to open a 3-1 lead in the series, can wrap up their third straight conference title - and a "three-match" against the Warriors - with a win in Game 5 on Thursday night in Boston.
Cleveland, which seemed sleepy at times in the regular season, went 12-1 in the Eastern Conference playoffs that ended with a win over Boston on Thursday night. They had a minus-30 points-per-game differential at home in this series, the worst-ever point differential at home in a best-of-seven series.
But as tension among Cleveland's home fans mounted at the Quicken Loans Arena, it was left to Irving to ride to the rescue with a sensational, momentum-changing display in the third quarter.
Irving said he was driven by the thought of the Cavs seeing their series lead vanish. "We have a bigger goal in mind".
"Playing in this league, you can't take anything for granted", Warriors guard Stephen Curry said after the Warriors beat the San Antonio Spurs 129-115 in Game 4 on Monday night.
But beyond James' foul trouble, the Cavs were having other issues as the Celtics outplayed them at both ends while opening a 16-point lead.
James, Irving and Love were the only three Cavs players to make double digits.
Once the sting of the loss to the Cavs wears off, the Celtics' 2017 playoff run will be remembered for Isaiah Thomas' valiant performance while coping with the death of his sister, a spectacular game 7 win over the Wizards, and a miraculous comeback win in game 3 against the Cavs.
Thomas told reporters Friday that he won't be able to determine a rehabilitation plan until the swelling subsides in his hip. "He was born for these moments".
"He has publicly said (Lonzo) won't work out, and that's what we have to go by", Ainge said. "It's just an effort all around". They're going to challenge us a lot, offensively, defensively, mentally, physically.
"Since I fell down in March, I think that's what aggravated it", Thomas said.
Game 5 takes place in Boston on Thursday.
"When you have a special player like Bron on your team, sometimes you can get caught watching and you allow him to be great", Irving said after Game 4. "The only thing that matters now is to get a win back in Boston".
Celtics coach Brad Stevens wants his team to find motivation in how the series played out after a fulfilling season.
Boston Celtics All-Star point guard Isaiah Thomas said surgery is not now the best option for his injured right hip although it could eventually prove necessary.