The fans at Camden Yards wanted to give the man a nice send off.
The Baltimore hitter lifted a routine flyball to right and it turned into a wild trip around the bases.
In what may have been his final home plate appearance with the Orioles, Mancini hit an inside-the-park home run in the fourth.
"I'm at a loss for words, I don't know what to say," he said.
The Orioles went 4-3 on a big homestand that included a four-game series against the Yankees and a four-game series against the Rays. They have put together a winning record in back-to-back months for the first time since 2016 and are in a much better position to make the playoffs than expected.
With the Orioles now in contention, it's not clear what they'll do with the two players that they could possibly trade. The Orioles went on a 10-game winning streak before the All-Star break, then held their own on this homestand.
When Mancini came up with one on and one out in the eighth, some fans stood and applauded. Josh Lowe couldn't locate the ball when he hit a fly to right. The ball hit the left side of his face and bounced away.
The Oriole's designated hitter took a curtain call before the ninth to acknowledge the crowd.
"After I put up my helmet, shin guards, elbow guard, and Tyler told me that they were calling my name, I went down to the tunnel and put my gear up." It meant a great deal. I don't know what the next few days will bring, but I wanted to soak in every moment today, just in case.
The Orioles have gone through a tough rebuild. He was named the Comeback Player of the Year in the American League after being treated for colon cancer.
Brandon Hyde said that he is someone that has gone through something. He has opened my eyes to a lot of things and I consider him a close friend.