Red Sox DH David Ortiz and Orioles pitcher Kevin Gregg clashed in the middle of the field on Friday night. (AP)

On the Red Sox bench, the tension built over the course of the at-bat between Sox DH David Ortiz and Orioles reliever Kevin Gregg. A game that the Sox led by a drama-free 10-3 score in the bottom of the eighth inning suddenly assumed a different complexion.

A fastball came inside. Then another, prompting Ortiz to glare at the mound. Then another, which came further inside and convinced Ortiz, bat in hand, to start walking towards the mound while yelling, and led both benches and bullpens to empty as players flooded the infield.

The Sox felt there was little doubt as to what was taking place, even as they wondered why it was happening.

“You go to the well three times, something’s looking pretty bad. I don’t know why they were trying to do that, but it was pretty obvious to me that they weren’t just trying to pitch him in,” said Sox starter Josh Beckett. “I hope [Gregg's pitches weren't a byproduct of the Sox having scored 10 runs]. We’re a good hitting team.

“You can’t just be hitting our [expletive] guys because we’re scoring a lot of runs. That’s how the game is played. Maybe they saw something different. Maybe they saw something they didn’t like or whatever. But if it’s just because we scored eight runs in the first inning and they start throwing at our [expletive] guys, it’s going to be a long year.”

“I didn’t see any reason for it, any reason to throw at him,” added catcher Jarrod Saltalamacchia. “Blood’s flowing, we’re obviously scoring some runs. It’s just hard to explain unless you’re out there. We’ve got to protect each other, protect our teammates.”

Order was restored, briefly. But on the next pitch, Ortiz (who was gone from the Sox clubhouse before it opened) popped up a 3-0 fastball to center field, a fly ball that should have been deep enough to score Josh Reddick, who was standing on third after a triple. Ortiz stood at the plate watching the flight of the ball before jogging to first. Gregg began yelling at the slugger, gesturing for him to run.

As the pitcher started shouting and drifting towards the slugger, he was thrown out by the home plate ump even as the play was still in process. But Ortiz was not appeased by the eject. After taking a couple moments to consider the matter, the burly DH accepted Gregg’s invitation to run, turning towards the mound and making a hard charge at the pitcher.

“You can see that Kevin was throwing pitches inside. That 2-0 pitch was pretty far in there,” said Sox first baseman Adrian Gonzalez. “Papi, when he mis-hits a ball, he always does the same thing. He didn’t do anything out of what he normally does. I think the umpire did the right thing in throwing out Gregg as soon as he saw Gregg saying something to him.”

“I was actually watching the ball, then you look down and there are two humongous guys going at it,” said second baseman Dustin Pedroia. “In that situation, you try to support your teammates and break it up.”

Immediately, the players once again started to flood the field in an effort to separate the two players. Marco Scutaro – listed generously at 5-foot-10 while weighing in at 185 pounds — was among the first players to reach the clash of the titans, where the 6-foot-6 Gregg and the 6-foot-4 Ortiz were throwing errant punches on the infield grass. The diminutive shortstop bravely thrust himself into the mix.

“I was pretty close. I was sitting on the little bench, where [Sox manager Terry Francona] always is, when the thing happened. I guess I was the first guy. I was just trying to hold him. He’s so tall that I was trying to hold him and I couldn’t even reach the ground. I had to jump on his back. … All of a sudden, I was right in the middle of the thing. I was just like hoping nobody would punch me.”

Josh Reddick was on third, in position to score easily on the flyout to centerfield. Yet after he started down the baseline, he never reached home plate, having diverted his route to intercede in the brawl.

After the field was cleared, Reddick was called out for having abandoned the basepath in what then became an inning-ending double play that took a run off the board for the Sox. Yet Reddick did not regret his decision.

“I was just going back and tagging, trying to get that run in. I put my head down to run, and next thing I know I hear the fans start going crazy. I look up and David’s halfway to the mound. What are you going to do? You’re going to go out there and help your team,” said the outfielder. “In that situation, you’ve got to go out there and help your teammates out. Luckily we had a nice little lead, so it didn’t really hurt us that much. You don’t want to get that bad mark above your head for not going out and helping the team out in that situation.”

Ultimately, the protagonists — Ortiz and Gregg — were kicked out of the game, as were Orioles pitcher Jim Johnson and Sox catcher Saltalamacchia. For his part, Saltalamacchia said that he wasn’t sure why he was ejected from the game. He was not alone in struggling to digest what had transpired in a game that had seemed straightforward but that took a late descent into chaos.

“A lot of craziness. Sometimes it gets hot, and guys get bothered. Those things happen,” shrugged Sox manager Terry Francona. “I didn’t see it.  There were too many big bodies out there. I’m sure we’ll get a chance to see it over and over and over.”