HOUSTON -- If you had the Astros reeling off their longest winning streak of the season behind a pitching staff that has been forced to turn to any healthy bodies they could find because of a wave of injuries, you might want to play a few lottery numbers.

Few could have envisioned that the Astros -- without ace starter Justin Verlander and several key relievers -- were going to be able to keep a competitive pitching staff together. And fewer could have imagined they’d dominate like they have in the last week.

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On Tuesday it was Zack Greinke turning in the best performance this year by an Astros starting pitcher, throwing eight scoreless innings, while rookie Andre Scrubb struck out Trevor Story to end the 11th and strand a pair of runners and keep the game tied. That set the stage for Myles Straw -- starting in place of banged-up center fielder George Springer -- to deliver a walk-off single through a five-man infield in the bottom of the inning for a 2-1 win over the Rockies at Minute Maid Park.

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“He had an awesome lineup over there off balance, looking for breaking balls, and he’d throw a fastball,” manager Dusty Baker said. “It was like he was almost in their heads with what they were looking for. He’d throw a fastball when they were looking for breaking balls. … He was awesome.”

The Astros have now won a season-high six in a row, allowing a total of seven runs in that span. Houston pitchers have a 0.96 ERA during the streak, including two gems from Greinke, who held the potent Rockies to three singles and no walks and struck out seven in a no-decision. He has a 1.84 ERA through five starts, including 0.44 in his last three.

“My endurance has been pretty good after that first start, and today I felt like my arm speed was starting to get better,” Greinke said. “Things felt a little crisper because my arm speed was a little better. Today, I thought, was the best start so far that I’ve felt health-wise, endurance-wise, stuff-wise.”

The problem for the Astros was that Rockies starter Antonio Senzatela was just as good. Facing a lineup without Springer (wrist), Yordan Alvarez (injured list) and Carlos Correa (rest), Senzatela threw eight scoreless innings, allowing three singles while hitting one batter. He struck out six.

Rockies manager Bud Black has seen Greinke continue to reinvent himself over the years. The Rockies have won their share of games against him by wearing him down and getting his pitch count up. Not this time. Greinke improved to 5-2 with a 2.70 ERA in 11 starts against Colorado since the start of 2018.

“You know he can pitch really well, even though the velocity was down a mile or two from his norm and what we’ve seen in the past,” Black said. “He still changes speeds. He still kept us off balance.”

Greinke touched 90 on the radar gun only twice while delivering 97 pitches, which were primarily four-seam fastballs (46), sinkers (21) and changeups (11). His best pitch was his last -- a 65-mph curveball that Sam Hilliard whiffed on to end the eighth after Greinke had set him up with an 86.2-mph sinker and an 89.2-mph four-seam fastball.

“This guy is just incredible to watch pitch, and his change of speed and his feel for things,” pitching coach Brent Strom said. “He’ll throw his changeup faster than this fastball sometimes. Figure that one out, but OK. … I kind of liken him to Phil Mickelson on the golf course. His short game is tremendous where he can spin the ball and do things that most people can’t do. I think he’s must-watch TV any time he pitches.”