Luka Doncic's Dallas Mavericks will "believe until the end" after they kept their NBA title hopes alive with a Game 4 victory over the Boston Celtics.

The Celtics headed to Dallas on Friday with the chance to clinch a first NBA Championship since 2008, up 3-0 in the series and looking to get the job done on the road.

However, Dallas dominated on their home court, cruising to a 122-84 blowout victory that means Boston will have to wait until at least Monday to seal a record-breaking 18th NBA title.

No team has ever come from 3-0 down in an NBA playoff series, but Doncic says his Mavericks team will not let that deflate their hopes of pulling off a hugely unlikely comeback.

"Like I said at the beginning of the series, it's first to four," Doncic told reporters. "We're going to believe until the end.

"So we've just got to keep going. I have big belief in this team that we can do it."

Doncic was facing criticism heading into Game 4 after fouling out in the latter stages of the previous contest, but he led the way with 29 points on Friday to help his team ease to victory.

Kyrie Irving believes Doncic proved the doubters wrong with his Game 4 showing, saying: "I think he made a few people eat their words in a healthy way.

"I think what you're seeing is him just taking accountability as best he can at this point in his life. He's a young person, still trying to figure it out. I give him that grace.

"I think it's just lessons being learned. When he is locked in like that, not paying attention to the refs, he's a huge, impactful player for us and a great leader for us. We want him to stay consistent on that and not be too hard on himself either."