NEW YORK -- Standing in one corner of the Houston Astros' clubhouse with a WBO championship boxing belt draped over his right shoulder, Lance McCullers Jr. deferred all the credit to catcher Brian McCann.

Sitting on a chair on the opposite side of the clubhouse, McCann appreciated the sentiment and spoke glowingly of McCullers.

Regardless of the credit, the battery duo helped the Astros continue the best start of team history.

McCullers pitched six scoreless innings and McCann slugged a three-run homer against his former team to lead Houston to a 5-1 win over the New York Yankees on Friday night.

"McCann, man," McCullers said when asked his key to success. "He's unbelievable back there. I think he really understands kind of how it works. He's unbelievable, so I give full credit to him. Just the way he calls the game, the way he settled down for me. From start to finish, he's unbelievable."

McCullers scattered four hits and ran his scoreless innings streak to 15 1/3 innings. He struck out seven without a walk and threw 90 pitches while lowering his ERA to 0.93 in his last three starts.

The right-hander has struck out 17 in 12 innings against the Yankees. He became the first Astros pitcher to toss at least six scoreless innings without a walk and at least seven strikeouts since left-hander Dallas Keuchel did it on Aug. 25, 2014, in New York.

"He's the real deal man," McCann said. "He's a top-of-the-rotation starter for somebody. I feel he's going to keep getting better and better."

Similar to Keuchel in Thursday's series opener, McCullers did his best work in the fifth and sixth innings.

McCullers struck out the side after allowing a leadoff double to Aaron Judge in the fifth. He gave up a leadoff single to Brett Gardner in the sixth and worked around a fielding error by third baseman Alex Bregman.

After Bregman misplayed Matt Holliday's grounder, McCullers got Starlin Castro to hit in a force play at second and got Jacoby Ellsbury to softly ground out to first base.

"Each time that they started to sort of get back in it or at least get in a threatening situation, he came up really big with some really (good) pitches," Houston manager A.J. Hinch said.

By the time McCullers finished his first scoreless road outing, his teammates gave him a 4-0 lead.

McCann slugged a three-run homer off Jordan Montgomery (2-2) into the second deck beyond the right-field wall with one out in the fourth and Carlos Correa hit an RBI single to right field in the fifth.

Houston added an insurance run on a run-scoring single by Josh Reddick off Aroldis Chapman in the ninth.

The combination of McCullers pitching to McCann and enough offense gave Houston (25-11) its best 36-game start in team history, surpassing the 1972 club's start. The Astros won their fifth straight and are 10-2 in their last 12 games.

McCann also was inadvertently involved in the ejection of Chase Headley with two outs in the seventh inning. Headley was tossed by plate umpire Adrian Johnson after recovering from an apparent finger injury while fouling off a bunt.

McCann asked his former teammate what happened and then a brief wild argument ensured.

"It's obviously pretty frustrating," Headley said. "It was OK. I needed to get some stuff off my chest. Thought I had some tough calls the last two games. And he gave me a reason to get upset."

The argument escalated when Johnson put a finger in Headley's face and began talking to the third baseman.

Said Johnson to a pool reporter: "So I stepped towards him and say, 'Why are you upset with me when you guys can replay that?' He starts to argue. He starts to yell. I start to yell and tell him that I'm not going to listen to it anymore. He kept yelling so I ejected him."

Headley's fourth career ejection was part of a frustrating night for the Yankees, who tied a season high with their third straight loss. New York avoided being shut out for the first time when Didi Gregorius singled in a run the ninth, but the game ended with Ronald Torreyes striking out.

"You're going to go through that," New York manager Joe Girardi said of the last three games. "You're not going to hit home runs every game."

Montgomery allowed a career-high four runs and eight hits in six innings. He also gave up a home run for the first time in 17 2/3 innings when McCann connected.

NOTES: Houston manager A.J. Hinch visited Monument Park for the first time and took a photograph of Mel Stottlemyre's plaque. He said he was planning on sending it to the former Yankee pitcher and pitching coach. Hinch said he got to know Stottlemyre when he worked with his son in the Arizona Diamondbacks' organization. ... New York DH Matt Holliday made his third start at first base. ... Yankees 2B Starlin Castro limped briefly after catching a popup by Houston 3B Alex Bregman in the sixth. He stayed in the game and gave manager Joe Girardi a thumbs-up signal. ... The Astros activated RHP David Paulino from the 10-day disabled list and optioned him to Triple-A Fresno.