BOSTON -- The Golden State Warriors felt they endured some questionable calls during their 92-88 loss to the Boston Celtics on Thursday at TD Garden.

Golden State got to the free throw line 19 times, compared to Boston receiving 38 attempts, and the Warriors were called for 24 fouls, nine more than the Celtics.

Celtics point guard Kyrie Irving took trips to the line seven times in the fourth quarter, and made all of them. However, some of his trips were viewed as suspect by the Warriors. Irving was 4-of-16 from the field, finishing with 16 points.

"He got to the free throw line a lot. That was it. He didn't make no shots," Draymond Green said after the game. "He got to the free throw line. Whether they were fouls or not is another discussion."

With 3:55 left, Irving brought the ball up the court with Klay Thompson defending. He drove hard to the left, initiating contact. Thompson kept his hands up to refrain from reaching, but he was assessed a personal foul. Stephen Curry, Andre Iguodala and Kevin Durant flung their arms in the air in bewilderment. Irving nailed both free throws, giving the Celtics a two-point lead.

At the 1:55 mark with the Warriors up two, Irving attacked Thompson again, but this time he drove to his right and lunged his body in the direction of the rim for a difficult shot. Thompson was trailing by half a step and caught Irving with some contact in the back and was assessed another foul. Thompson couldn't believe it, as he walked away from the play to avoid being called for a technical foul. Durant and Iguodala threw their hands upward in disgust.

Irving walked to the line and drilled the pair to tie the score.

But the most controversial call occurred with 14 seconds left with the score tied at 88. Green switched onto Irving at the top of the key. Irving crossed Green over a bit, penetrated and attacked two Warriors' defenders in the paint. Green recovered, also challenging the circus layup attempt from behind as Irving spilled awkwardly to the floor. The ball clanked off the rim, but Green was hit with a foul.

This time, all five of the Warriors' players reacted to the call. Head coach Steve Kerr was irate.

"I just watched the tape. There was no foul. Tough call," Kerr said following the game.

Kevin Durant and the Warriors saw their seven-game win streak snapped by the Celtics, who in turn have won 14 straight. David Butler II/USA TODAY Sports

Irving connected on both free throws to go up two. The Celtics wouldn't give up the lead again and went on to extend their league-high winning streak to 14 while snapping the Warriors' streak at seven.

Thompson was whistled for three fourth-quarter fouls, all of them while defending Irving.

"I guess, I can't foul," he said sarcastically. "I have to give him more space when he drives, I guess. That's what I'll do next time."

Durant provided a glimpse of his frustration level with the free throw disparity, but he kept his emotions in check.

"At the end of the game, they shot six free throws," he said. "I thought it was great defense. ... It's hard to play like that. But on the other end, I think we got to execute better on the offensive end."

Celtics coach Brad Stevens says he encourages his guys to stay in attack mode.

"We talk all the time about we want to get free throws, layups or 3s and play inside-out and we made an emphasis on that at the start of training camp," Stevens said. "You don't always get to the line quite as much, but I thought we really drove it hard. They are so hard to score on, you have to convert when you do get to the line."

When asked if the Celtics are on the Warriors' championship level, Thompson quickly dismissed that notion.

"Nah, it takes a lot of basketball to get there," he said. "...They have a better record than us. You can say they're better than us right now."

Boston appears to be a legitimate threat in the Eastern Conference. For three consecutive years, it has been the Warriors and Cleveland Cavaliers in the NBA Finals.

Might this be Boston's year?

"It's very, very likely, right?" Curry said. "They're playing the best right now in the East and obviously until they beat Cleveland, who's done it three years in a row -- so we'll see, but I hear the weather is great here in June."