Pirates starter Chris Archer threw a 93 mph fastball behind Reds first baseman Derek Dietrich's back to spark the incident. Dietrich had homered in the second inning and had stared at his blast before circling the bases, apparently angering Archer.
Warnings were issued to both teams, but Bell came onto the field to argue with home plate umpire Jeff Kellogg that Archer should have been ejected. Players from both teams then began to push one another.
After the situation seemed to settle down, Puig charged toward Pirates pitcher Trevor Williams at home plate and had to be restrained, reigniting the incident. Puig grabbed Pirates bench coach Tom Prince and tried to put him in a headlock.
"I was trying to go in,'' Archer said. "I air-mailed a couple balls today, a couple that I was trying to elevate, a couple that I yanked when righties were up there. Another one that I just yanked.''
"I missed -- missed my spot,'' he added.
Puig said pitchers shouldn't try to hit batters because a batter can't retaliate in the same way.
"When people watch the ball go far away or do bat flips, like I do before, in the next [at-bat] try to strike out the guy,'' Puig said. "Don't try to hit the guy, because we can't defend you back because we can't hit you with a bat or nothing.''
Dietrich's 436-foot drive to right-center gave the Reds a 2-1 lead. Dietrich dropped his bat and stood in the batter's box and watched the ball clear the fence atop the Clemente Wall and bounce into the Allegheny River.
Pirates catcher Francisco Cervelli had words for Dietrich when he crossed home plate. Dietrich said that exchange of words probably resulted in the fourth-inning hostilities.
"That's probably where it started. I didn't say anything, I didn't flip my bat, nothing on my end. So people see it differently. Most hitters see it as a good swing, some pitchers see it as 'Oh he's trying to show me up.' I don't know where the game's going these days," he said. "Everyone loves to play and have fun, but I let my bat do the talking. It was good to see the guys had my back, especially my manager. We're not trying to intentionally hurt anybody; we're just trying to play baseball, play hard, but unfortunately things happen."
Vazquez said he was ejected for entering the field without his uniform top. The reliever, said Dietrich, who was designated for assignment this offseason, hasn't earned the right to do something like that.
"He shouldn't have done that,'' Vazquez said. "If you do something like that, you're going to pay for it. We're trying to play the game like we have to, respect the game. He shouldn't do it. Joey [Votto] can do it because he's been here a long time, but for a guy like that, he's not supposed to do something like that. ... I think it was a little too much.''
He also tweeted after the game:
Protect the ship no matter what🥊— Nightmare Vazquez (@F_Vazquez73) April 7, 2019
Bell said after the game that "it's just completely unacceptable for anyone to try to intentionally hurt one of our players. It's that simple. And it was obvious.''
Matt Kemp replaced Puig, while Archer was allowed to remain in the game after the incident. The Reds led 3-2 at the time, but the Pirates scored two runs in the bottom of the fourth to take a 4-3 lead.
Dietrich homered again in the eighth inning, a 418-foot shot to right field, with the Reds down 7-3 at the time.
The Associated Press contributed to this report.