Porter didn't miss a beat, calling for a challenge that overturned the call and gave the Astros their first inside-the-park homer since Jose Altuve did it against the Giants on Aug. 20, 2011.
"[Blue Jays manager John] Gibbons was headed to the mound for a [pitching] change, and at that point you have to get it in before the change is made," Porter said. "Our video team did a great job of getting the word to us quick."
Replays showed Singleton's leg slid below a high tag from Toronto catcher Josh Thole despite the ball beating Singleton to the plate by a clear margin.
That juxtaposition meant both player and manager were anything but certain that Singleton was safe.
"No, I didn't know [if I made it]. It was very close to be honest," Singleton said. "It could have gone either way."
Porter said it's those plays when perception often trumps reality that makes replay such a useful system.
"On full speed, I thought he was out because the ball beat him there," the skipper said. "But that's the advantage of replay, that's the advantage of having all the angles they have up there in the video room."
A brief review followed and confirmed what the screaming home fans could already see from a replay on the video board.
According to Singleton, it was the rookie slugger's first inside-the-park homer at any level of baseball. It meant consecutive two-run homers for the Astros in an eighth inning that capped a second straight win over the Blue Jays.
Robbie Grossman had just preserved the Astros' tenuous 4-2 lead with a leaping grab to rob pinch-hitter Juan Francisco of a potential game-tying two-run homer to end the top half of the eighth.
Turns out the fun was just getting started. Jason Castro roped a two-run homer to left for insurance runs and L.J. Hoes singled to bring Singleton to the plate.
The first baseman hammered a high fly ball to the right-center-field bullpen fence, and the ball careened toward center, causing Toronto outfielder Anthony Gose to slip.
"Once I saw Anthony kind of slip, I turned the burners on ... I just kept running," Singleton said.
Back-to-back two-run homers and a wild finishing kick to a game that had already seen Jose Altuve score from first after R.A. Dickey's pickoff attempt went awry and Danny Valencia's cross-diamond throw to third bounded away, allowing Altuve to score the go-ahead run in the fifth.
"It was great, it was exciting, and one of those games and innings we can build off of," Singleton said.
Porter's successful challenge makes him 13-for-22 on replay reviews this season.