SAN DIEGO -- A trip to the World Series hung in the balance when Rays manager Kevin Cash made an early appearance on Friday night. With two Astros on board in the fifth inning, Cash hopped off the top step of his dugout, waved his right hand and began a slow walk toward the mound to greet a displeased Blake Snell.

Snell, Cash’s lefty ace, hadn’t allowed a run, and had been mostly effective in Game 6 of the American League Championship Series at Petco Park. But Cash had gone to this well before. The Rays' bullpen had inherited 20 runners this postseason. None had scored.

Cash summoned a well-rested Diego Castillo for the trio of Astros right-handed hitters due up. Snell rolled his eyes and placed his left hand defiantly on his hip, then barked at no one in particular as he made his exit.

The stage was set for a potentially series-defining inning. Houston seized the opportunity.

A parade of hits later, the Astros had turned a one-run deficit into a three-run lead. They were on their way to a 7-4 victory, continuing their stunning turnaround after losing the first three games of the series.

“That was the difference in the game,” said Houston manager Dusty Baker when asked about the fateful fifth.

The Astros, of course, are now three-quarters of the way to joining the 2004 Red Sox as the only teams to overcome a 3-0 deficit to win a best-of-seven series. In fact, those Red Sox are the only other team to force a Game 7 under such circumstances.

Cash, doing his best to ensure that the series wouldn’t get that far, called for Castillo, one of his best relievers, in the game’s highest-leverage spot. The move, in his eyes, was a no-brainer.

“Look, it was fairly clear,” Cash said afterward. “I thought the way [Astros starter Framber] Valdez was throwing, there wasn’t going to be a ton of scoring opportunities for us. Just wanted to get the ball into Diego’s hand. That was a big moment, first and second, no outs. Blake’s pitch count was manageable. But I trusted that Diego could come in there and basically do what he’s done all season long.”

Now it was Baker’s turn to counter Cash’s maneuvering. Baker called for Martín Maldonado to bunt, and the catcher dropped a perfect one up the third-base line, advancing the runners to second and third base for the top of the lineup.

In an ominous sign of things to come, Castillo’s first pitch to George Springer squirted off the glove of catcher Mike Zunino -- not far enough to score the runner, but just far enough to rattle the nerves.

The Rays drew their infield in and shifted three batters to the left side. Springer responded by shooting a single through the vacant right side, giving Houston a 2-1 lead -- both runs charged to Snell, who voiced his displeasure afterward.

“Cash is really good at his job and really good at what he does, but I’m going to disagree with him, it’s going to happen,” Snell said. “Especially because I’m a guy that wants to be out there. I want to go as deep as possible.”

After the game, Baker noted that the Astros' rally undoubtedly made absent third-base coach Gary Pettis smile. Pettis left the Astros on Sept. 15 because of discomfort in his hip, which led to the diagnosis of multiple myeloma, defined as a cancer of plasma cells.

“Maldy, he's worked on his bunting, and then, George -- that was perfect,” Baker said. “I'm sure Gary Pettis was very happy, because every day in BP, he stands at second base and dares George to try to hit him, and he hasn't hit him yet. George would have hit him today.”

It was hard to fault Castillo for Springer’s shift-beating single -- with a .190 expected batting average. But on the very next pitch, Castillo hung a slider that Jose Altuve pulverized into the left-field corner for an RBI double. After Zunino again could not squeeze a Castillo slider, Altuve went to third, and Carlos Correa singled him home.

“We’re relentless,” Correa said. “We keep coming, you know? We said we didn’t wanna go home, and we meant it.”

In the Rays' dugout, the Astros’ barrage was jarring considering Castillo’s October track record. In 13 postseason innings before Friday, he hadn’t been scored upon -- whether his own runner or an inherited one.

The Astros, in the blink of an eye, had a four-spot. The Rays, whose bullpen had bailed them out of every prior jam, were left wondering what hit them.

“Pretty gut-wrenching feeling,” Cash said.

If there’s a silver lining for Tampa Bay -- and with the Rays on the brink of making some dubious history, it takes some digging to find one -- it’s worth noting how quickly things unraveled on Castillo.

His day was done after 14 pitches. For all intents and purposes, so was the game. Cash avoided his big-time bullpen arms the rest of the way, meaning his entire “stable” should be available for Game 7.

A Game 7 that -- judging by his decision-making in the fifth -- Cash had hoped to avoid at all costs.