PHILADELPHIA -- Jay Bruce has been one heck of a savior for the Phillies. Maybe Vince Velasquez can be one, too.

Bruce bashed his record-setting fourth home run in four games with the Phillies in the fifth inning of Friday night's 4-2 victory over the Reds at Citizens Bank Park. His two-run, opposite-field homer against right-hander Tyler Mahle handed them a 2-1 lead, helping them maintain their two-game lead over the Braves in the National League East. Bruce is the first Phillies player in the modern era to hit four homers in his first four games with the team, according to Elias Sports Bureau.

• Box score

"It's definitely a shot in the arm," Bruce said about joining a postseason contender. "I know it is my 12th year and I have been to the playoffs five times. I feel very fortunate that I have been able to do that. But the playoffs and winning baseball and championships are very fleeting. They are very, very hard to come by. And I want to be a part of that. And to have a chance on this team that I think has a legitimate chance to play a long time this year, it is something I definitely don't take for granted. And I just want to keep on helping."

The Phillies acquired Bruce and cash on Sunday from the Mariners for Class A infielder/outfielder Jake Scheiner. The Phillies wanted Bruce to fortify their bench and outfield, but he turned into an everyday player following Monday’s season-ending knee injury to center fielder Andrew McCutchen.

Bruce homered twice in his first start Tuesday against the Padres in San Diego. He homered again Wednesday in the series finale. It is the 14th time in his career he has homered in three consecutive games, with a career-best five homer streak July 23-27, 2016, when he played with the Reds.

Bruce is batting .295 with 11 home runs, 29 RBIs and a .929 OPS in 29 career games at Citizens Bank Park. It is his second-highest OPS in any park with 45 or more plate appearances. Only Houston's Minute Maid Park (.966) has been better.

"It doesn't really matter to me a whole lot, honestly, where I play as far as that goes," Bruce said. "But I am excited to play in front of people. A lot of them. That's what I am excited about. And obviously that's not taking anything away from the other situations I have been in. This place is just different. It's good. I am excited about it."

"I wanted to back-door a curveball, and I don't know if he was sitting on it or just put a good swing on it," Mahle said. "Whatever he did, he did it well."

Phillies right-hander Zach Eflin allowed one earned run in 6 1/3 innings, and left-hander Jose Alvarez picked up two outs in the seventh, handing the ball to Velasquez in the eighth. He pitched a perfect frame with a one-run lead, which was huge considering his recent move to the bullpen and the rash of injuries that has decimated it.

The Phillies placed Seranthony Dominguez on the 10-day injured list Friday with an injured ulnar collateral ligament in his right elbow. He is seeking a second opinion, but he could be headed for season-ending Tommy John surgery.

Dominguez joined six other relievers on the IL. The Phillies' bullpen currently includes Hector Neris, who picked up his 13th save in 13 opportunities with a scoreless ninth; veterans Juan Nicasio and Alvarez; Velasquez; and Edgar Garcia, J.D. Hammer, Austin Davis and Ranger Suarez, who have a combined 60 games of experience among them.

"We lose a guy who took on high-leverage innings for us, and if we can gain one in Vince, it makes the blow a lot less powerful," Phillies manager Gabe Kapler said. "It's going to be a blow nonetheless, but it certainly softens it."

Velasquez got Jesse Winker to ground out to open the eighth. He struck out Yasiel Puig swinging on a 1-2 slider and Jose Iglesias on a 1-2 fastball that hit 96 mph.

"He was absolutely disgusting," Eflin said. "I made sure to tell him when he came in here how special he was tonight. You can't teach that stuff. It's really unhittable."

"I know it's a big role in that situation," Velasquez said. "It's a different mindset going into that inning, but I'm fully capable of gathering preparation, my mindset physically, mentally, whatever it may be to come in and close the doors in that inning and then allow Neris to come in and shut the door like he did today. Today was a great demonstration of what could continue happening."