ATLANTA -- A.J. Burnett was uncharacteristically unable to keep the ball in the yard and the heart of the Braves' order benefited to send the Pirates to their third loss in four games on Monday night.

Burnett gave up three home runs in a game for the first time in over two years and went only five innings as a result, as the Bucs dropped 3 1/2 games behind the first-place Cardinals in the National League Central race with a 7-2 loss in the series opener at Turner Field.

The loss was highlighted by the early exits of catcher Russell Martin and manager Clint Hurdle, who were ejected for arguing balls and strikes in the bottom of the fourth inning.

Burnett gave up a two-run home run to Braves catcher Brian McCann earlier in the fourth before emotions boiled over, and allowed two more two-run shots in the fifth to Jason Heyward and Freddie Freeman with his manager and batterymate inside the clubhouse. In all, Burnett allowed six earned runs and eight hits, both season highs.

"You're going to have games like that once in a while, everybody does," Hurdle said. "That's the first one [Burnett's] had this year, first one he's had in a while, so we'll move on."

Once again, the Pittsburgh offense could not offer the 36-year-old right-hander any run support to speak of, finishing with nine hits, but stranding seven runners. The Pirates have scored two runs or fewer in five of their last seven games.

Burnett gave up a double to Chris Johnson in the fourth inning following McCann's go-ahead home run before retiring the next two batters to bring up Braves pitcher Kris Medlen.

Burnett's first pitch to Medlen appeared inside for a ball, and the righty exchanged words with home-plate umpire Dan Iassogna before returning to the mound. Iassogna called a ball on the next pitch, which appeared inside but lower in the zone, and then ejected Martin as the catcher stood up to throw the ball back to the mound. His ejection prompted Hurdle to emerge from the dugout in order to take up the argument for his catcher. Hurdle received his third ejection of the season moments later.

Martin, who said after the game that he normally gets along with Iassogna, appeared shocked that he had been ejected for a remark directed at himself.

"The umpire didn't call a pitch that I thought was a good pitch, and I stood up and I [cursed], and he threw me out," Martin said. "That's the way it happened."

The Braves opened the floodgates in the next inning, when Jason Heyward roped a 1-0 changeup from Burnett around the right-field foul pole for his first home run since an April 22 appendectomy that sidelined him for nearly a month. Then, after Justin Upton's single through the right side, Freeman took the first pitch he saw out to left for an opposite-field home run to extend the Atlanta lead to 6-1.

"I wasn't able to put that behind me," Burnett said. "I was making pitches early, and then in that last inning I wasn't able to make pitches and got behind hitters. It's a good lineup, a good swinging team, and you can't get behind them, especially throwing cookies in there when you do get behind them."

"We were able to lay off the pitches that were in," McCann said. "We all got in some hitters' counts there in that one inning and he had to throw it over the plate. We were able to capitalize on that."

The Pirates jumped out to a 1-0 lead in the third inning on a ground-rule double by Gaby Sanchez that scored Neil Walker from second base. After Walker was hit by a pitch, Garrett Jones flied out to B.J. Upton in shallow center field, Upton's attempt to double off the runner at first base sailed high, allowing Walker to move up a station. Then Sanchez stepped in and took Medlen's 3-2 fastball deep to right-center field, clearing the wall on one bounce to bring Walker across.

There were some positives for the Bucs, such as Burnett's first hit, and the relief work of Ryan Reid and Jared Hughes, who were added to the roster Monday afternoon.

Reid worked 1 1/3 perfect innings after entering with the bases loaded in the bottom of the seventh. He induced a groundout by Reed Johnson to end the threat, then retired the Braves on three straight grounders in the eighth.

Hughes came on in relief of Burnett, allowing one hit in one inning to lower his ERA to 4.30.

But on a night where the strike zone was not where he sometimes felt it should be, Burnett and the Pirates paid for the mistakes he made up in the zone and over the plate. The result was his first game surrendering three home runs since May 16, 2011, as a member of the Yankees. He had given up just four home runs this season heading into Monday.

"Sometimes you have to [adjust your approach]," Burnett said. "Sinker in has been a big pitch for me, and when you don't get that pitch, you can't keep throwing it, it's going to be a ball. So you gotta kind of make the adjustment, and McCann made his."