PHILADELPHIA – Boom, boom, boom.

A few Phillies fans had not even left Questlove’s vegetarian cheesesteaks line at Citizens Bank Park on Monday night, when they looked up to see the D-backs had hit three consecutive home runs to open the game. But if they thought the game could not get any crazier they were wrong. If they stayed until the end, they witnessed baseball history, because the D-backs and Phillies hit a combined 13 home runs, setting an MLB record.

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The D-Backs hit eight homers in their 13-8 victory. The Phillies hit five.

“These are not the type of baseball games that we like to be in,” Phillies manager Gabe Kapler said.

But these are the games the Phillies have been playing too often this season. The Phillies, who fell into a first-place tie with the Braves in the National League East, have allowed a National League-leading 108 home runs. They are on pace to allow 265. It would shatter the Phillies’ franchise record of 221, which they set in 2017. It would set a new Major League record, which the Reds set in ‘16 when they allowed 256.

The Phillies allowed 171 homers last season.

Of course, home runs are up across baseball. The Orioles, Mariners and Angels each have allowed more homers than the Phillies.

It does not make this OK.

“It's definitely a problem,” Kapler said. “It's definitely something we have to get out in front of and figure out how to solve. That's a lot of work on the part of the staff. That's our responsibility to get out in front of that."

Phillies right-hander Jerad Eickhoff continued a troubling trend that had Kapler noncommittal about Eickhoff making his next scheduled start Sunday in Atlanta. Eickhoff went 2-1 with a 1.50 ERA in his first five appearances this season, including four starts, not allowing a single home run in 30 innings. But after he allowed five hits, seven runs, two walks and five home runs in three-plus innings against the D-Backs, he is 1-3 with an 8.89 ERA in his last six starts -- and has served up an alarming 16 home runs in 27 1/3 innings.

"I think these are things we need to talk about after the game, and probably not there yet," Kapler said about Eickhoff’s spot in the rotation.

The Phillies have some options in Triple-A in left-hander Cole Irvin (2-1, 5.48 ERA in four starts with the Phillies) and right-hander Enyel De Los Santos (2-2, 3.65 ERA in six starts with Triple-A Lehigh Valley, 6.43 ERA in four relief appearances with the Phillies). Right-hander Vince Velasquez opened the season in the rotation, but the Phillies seem intent on keeping him in the bullpen.

“Yeah, I expect to make the next start, and I’m going to show up tomorrow and work,” Eickhoff said. “That’s what I’ve always done and nothing really changes. I’ve just got to execute a little better and move on.”

Eickhoff allowed a first-pitch, leadoff home run to right field to Jarrod Dyson in the first. Ketel Marte followed, smacking a 2-2 curveball to right for back-to-back home runs. David Peralta hit a 3-2 slider to right for back-to-back-to-back home runs. It was the first time in Phillies history that they had allowed three consecutive home runs to start the game. It was the seventh time it happened in baseball history.

Eickhoff retired nine consecutive batters before things fell apart again in the fourth. He allowed a two-run homer to Eduardo Escobar and a two-run homer to Alex Avila to make it 7-3. Phillies left-hander Ranger Suarez replaced Eickhoff. He allowed two more home runs. Austin Davis allowed another homer in the ninth.

“I think they had a really good plan,” D-backs manager Torey Lovullo said. “I think we had a really good approach. We were sitting on particular pitches in certain counts at certain times, and we executed.”

It was the fourth time in Phillies history they had allowed at least eight homers in a game. It last happened on Aug. 24, 2015, when they allowed eight against the Mets. They allowed a National League record nine homers to the Reds on Sept. 4, 1999.

Scott Kingery homered twice for the Phillies. Jean Segura, Rhys Hoskins and Jay Bruce each hit solo home runs.

“For some reason, the ball was just absolutely flying,” Kingery said. “It felt like every ball that went in the air was a home run. I’m not sure if that had to do with the weather, the humidity, I don’t know. It was just crazy out there.”