ANAHEIM – What was that? Will Harris cracked a smile while walking off the mound? All it took was something immaculate for Harris to do something his teammates say is even more of a rarity.

Harris, the dependable, stoic relief pitcher and the dean of the Astros' bullpen, struck out the side on nine pitches for an immaculate eighth inning in the Astros’ 4-0 win over the Angels on Friday night. It was the first immaculate inning by an Astros pitcher since Brandon Backe on April 15, 2004, against the Brewers, and only the sixth in franchise history.

• Every immaculate inning in MLB history

Harris, who struck out Kaleb Cowart, Matt Thaiss and Michael Hermosillo, couldn’t help but smile as he walked off the mound, which didn’t go unnoticed by his teammates.

“I’m pumped for Will, because Will never smiles ever on the field,” third baseman and fellow LSU product Alex Bregman said. “He’s always in a bad mood. He’s always grumpy. That was the first time I’ve ever seen him smile on a baseball field.”

Harris said he had good command in the bullpen and started to think about the possibility of striking out the side on nine pitches when he whiffed Cowart to start the eighth.

“It was kind of weird,” Harris said. “Once it got to two of them, I was like, ‘All right, that’s only six pitches. Let’s try and do it.’ I actually slipped on the curveball to Hermosillo and threw it for a ball, but he swung at it. I got lucky there. I was able to get it done.“

And what about that smile?

“They always mess with me and say I’m always mad about something when I’m coming out of the game,” Harris said. “So whenever it kept going, they were like, ‘The only way he’s not going to be mad is if he strikes them out on nine pitches here.’ It kept going -- six, seven, eight and then nine -- so they all had a good time with it. It was fun.”