After being ejected in the ninth inning of the Nationals' victory over the Tigers, Bryce Harper tells reporters he was surprised and upset about the umpire's decision. (0:42)

WASHINGTON -- Bryce Harper was ejected from the dugout in the ninth inning of the Nationals' 5-4 comeback win over the Detroit Tigers on Monday and then yelled at plate umpire Brian Knight as the Nationals celebrated the victory.

The ejection, Harper's first of the season and seventh of his career, occurred after Nationals shortstop Danny Espinosa was called out on strikes by Knight to start the bottom of the ninth. The next batter, pinch-hitter Clint Robinson, sent a home run just over the right-field fence to give Washington the win.

"Everybody was up on the steps, preaching about what they thought was going on," Harper, last year's National League MVP, said after the game of the Espinosa out. "[Knight] kind of picked me and said, 'See ya later.' I think my emotions showed that I was pretty surprised, but, you know, I think Clint Robinson made me really excited, hit the walk-off, and we got the W, so that's all that matters about tonight."

As Harper and the Nationals mobbed Robinson at the plate, cameras captured Harper pointing at Knight and yelling. Following the game, Harper did not deny the exchange.

"Yeah, absolutely," he said. "I was pretty upset. I think I was right to do that. Let him hear what I have to say, let him hear it again, and so what? Couple choice words. If I do [get fined], I do. I'll pay it. So I think it deserves to, you know, maybe he'll get fined, too. So we'll see."

On Monday, Harper went 0-for-2 with two walks, one of which was intentional. In the fourth inning, he struck out on three pitches, two of which were called strikes, including the third strike.

"It's an emotional game. He's an emotional young man," manager Dusty Baker said of Harper. "You certainly don't like him to get tossed, but every once in a while, you gotta blow off some steam or else you go crazy. I'm sure it won't happen again."

Baker went out to argue with Knight after Harper's ejection. After the game, Baker said Knight told him that he had considered kicking out Harper earlier in the game.

Harper barked at Knight after being called out on strikes in the fourth inning. It was a three-pitch at-bat in which two of the strikes were called.

The Associated Press contributed to this report.