CLEVELAND — The Cavaliers’ season was hanging by a thread and the Knicks were giving them chances to stay alive. Missed shot after missed shot in a fourth quarter in which they hit only 21.1 percent of their field-goal attempts.

There was only one problem for the home team: Mitchell Robinson was standing under the basket to either extend possessions or throw down dunks on the errant shots.

The pre-series favorite had no answer for the 7-footer Wednesday night, or for the entire five games of the matchup for that matter.

“I thought the way Mitch played just set the tone for everything,” coach Tom Thibodeau said after Robinson scored 13 points, added 18 rebounds and three blocks to help send the Knicks to the Eastern Conference semifinals for the first time since 2013.

Entering the series, there was significant talk about Cleveland’s two big men, Defensive Player of the Year finalist Evan Mobley and All-Star Jarrett Allen. Robinson was asked about that, and expressed confidence in his own way.

“What you mean? We good. We straight, too! What you talking about?” he asked a reporter when it was brought up that the Cavaliers started two legit bigs.

Mitchell Robinson blocks Darius Garland’s shot during the Knicks’ 106-95 Game 5 series-clinching win over the Cavaliers.
Charles Wenzelberg/New York Post

He backed up that talk with dominance, overwhelming the Cavaliers in the paint.

On Wednesday, Robinson took it to another level, hauling in 11 offensive rebounds — seven more than the Cavaliers managed as a team.

In fact, Robinson and Josh Hart combined for 30 rebounds, which was as many as the Cavs accumulated.

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“I’ve said this all along, I think he’s the best offensive rebounder in the league,” Thibodeau said. “Oftentimes, he’s got two bodies on him and they’re making a conscious effort to keep him off the glass. And now his defensive rebounding is coming along also. That rebounding piece is huge. The shot blocking, the rim protection, the pick-and-roll defense, and his offense is starting to come as well.”

Hart, a standout rebounder for a guard, and Robinson have developed somewhat of a rebounding rivalry, pushing each other on the glass. Hart was mic’d up during Game 4, and bragged to Robinson that he retrieved offensive rebounds that crushed teams. Wednesday night, Robinson had reason to gloat.

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“So me and Josh got competitive about it and I won this one,” he said. “I even snatched one from him.”

After missing the postseason two years ago due to a broken foot, Robinson made his mark this time. He averaged 9.8 rebounds and 2.2 blocks over the five games. He was one of the best players in this one-sided series.

“It was great. First time in the playoffs,” Robinson said. “Derrick [Rose] tells me all the time: ‘Anchor the defense,’ before every game. So it was something I needed to do and we got it done.”