"That's baseball," Gregerson said. "One pitch can change the entire dynamic of the game."
And the standings. Oakland fell a game behind the Angels, who beat the Marlins, 8-2, in the American League West -- a reminder that there's little room for error amid such a crucial stretch.
Gregerson easily retired his first batter and nearly his second, but second baseman Eric Sogard's throw on Robbie Grossman's routine grounder was dropped by first baseman Stephen Vogt. Gregerson proceeded to hit Jose Altuve -- "I tried to quick-pitch that first one just to keep the guy at first honest and it just got away," he said -- to bring up Carter with just one out.
"It's a normal throw from Sogie, and it just hit off the thumb of my glove. It's inexcusable, obviously," Vogt said. "I wish I could say this or this happened, but just one of those things where I didn't believe it myself until after I missed it. I'd like to say, throw that ball 99 out of 100 times, obviously it's going to be caught. You shouldn't even have to say that because the ball should be caught, so obviously not thrilled with myself. It definitely changed the momentum of the inning. Big play."
"Doesn't happen very often," said manager Bob Melvin.
What Carter did next does, though. It was the second homer of the series and 32nd overall for the designated hitter, whose five long balls off Oakland are his most against any team.
Carter was once theirs, before the A's packaged him in the Jed Lowrie deal last spring.
"I was trying to throw a sinker down and away, and it started away and just ran all the way back across the plate, down and in," Gregerson said. "Not necessarily a bad location for a lot of guys, just not for him."
"Chris Carter, I'll tell you what, he's putting together some kind of season," Astros manager Bo Porter said. "And the home runs are getting bigger and bigger."
Gregerson dropped to 3-3 with the loss, while Hammel, throwing on 10 days' rest, was forced to swallow a no-decision despite a highly encouraging performance.
He's done this before, flashing the kind of stuff that is a reminder why the A's traded for him in July. He's just yet to do it consistently, though Tuesday's solid outing against the Astros likely secured him more time for an opportunity at just that.
It was just Hammel's second quality start in eight tries with the A's. The right-hander allowed a fourth-inning leadoff homer to Dexter Fowler but just two other hits and one walk. He fanned six and retired each of his final 10 batters, including four on strikeouts.
Less than a month ago, pitching on the same mound, Hammel allowed eight runs in 4 1/3 innings.
"I'm sure his last start here was on his mind," A's left fielder Jonny Gomes said. "Maybe that little bit of extra rest gave him some help.
"Hammel's a heck of a pitcher. He throws hard and has that big hook. He's just run into some tough luck at times. His start tonight was A-plus, excellent job. At the same time, it shouldn't surprise you, because that's the type of guy he is."
Hammel got plenty help from his defense in the one-run outing. Gomes not only saved two runs with a superb diving catch in left field to end the third -- "That's max extension for me," he said -- but also provided a pair of hits, including a first-inning RBI single to give the A's a quick 1-0 lead. Nate Freiman contributed an RBI double in the fourth.
"Definitely the best since I've been here," Hammel said. "I felt very collected, throwing with conviction, being aggressive and getting ahead of guys. That's usually a pretty good formula. Outstanding defense, too."
"That's about as well as he's pitched, certainly the later innings," Melvin said. "Good for his confidence. He's going to have some big starts for us down the stretch."