Chris Bosh ended last season collapsed in an AmericanAirlines Arena hallway, dazed and despondent after the devastating Finals defeat to Dallas.

He ended this season smiling with the championship trophy in one hand and his seven-week-old baby in the other, the euphoric culmination of the two most memorable months of his life.

A position shift to center.

The birth of a son, Jackson.

A painful injury that sidelined him nine games this postseason.

A splendid performance in Game 7 of the Eastern Conference Finals.

And finally, a championship.

This June, the searing image is not of Bosh on that hall floor, writhing in emotional distress, but instead of Bosh lifting the treasured trophy skyward and carrying it off the court.

“That,” Bosh said, “was everything to me. It was just erasing all those memories, getting that bad taste out of my mouth. I live with that every time I walk down the hall. I forgot cameras were there last year, but whatever.

“But I think it was good for me in the long run because I could watch every single day what we had to go through and what I had to go through. So any time that I was thinking about just taking a play off or taking some time off or not working that day, doing the easy thing, I thought about that moment.

“Every loose ball that was around this year and this postseason, I thought about that moment, and that helped me build my will, and it helped me get to this point.”

Different position

Bosh envisioned winning a championship here but did not expect it to happen with him playing center. But on April 12 in Chicago, coach Erik Spoelstra moved Udonis Haslem into the starting lineup at power forward and shifted Bosh to center.

Bosh had played center before for the Heat, but this was different. This would mean playing it virtually all of the time he was on the court.

He said that during the 2010-11 season, he was “shell-shocked” when asked to play center, which is often more physically taxing on his 6-11, 235-pound frame.

“I was still fighting it a lot last year for like, the ninth year in a row,” he said.

But this time, he did not.

“I just had a conversation with myself,” Bosh said. “I had to own up to it and accept it. If we’re at our best when I’m at center, then so be it. I knew that Spo and the coaching staff saw something, saw some way that I could help. After they asked me to move to [center], I didn’t fight it. I just wanted to be the best big man I could be.”

Bosh’s willingness to change positions allowed Spoelstra to make more use of a smaller lineup with only one natural power rotation player. That lineup wreaked considerable damage this postseason.

“A big step was Chris embracing the center position,” Spoelstra said. “And that really took our team to another level because of his speed, his skill set. He could defend multiple positions. As a center, he became one of the toughest covers in the league.

“He really had to sacrifice quite a bit and to get out of his comfort zone and things that he was used to in Toronto. That helped us take another big step forward as a team.”

Bosh missed the final six regular-season games with a hamstring strain, returned to start the Knicks series, then experienced a night he will always remember.