A total of 309 pitches were thrown between the Red Sox and Astros in Game 4 of the ALCS on Tuesday night. One stands out above the rest.

With the game tied, 2-2, and the potential go-ahead run on second base, Sox starter-turned-reliever Nathan Eovaldi found himself in a two-out battle with Astros catcher Jason Castro. Eovaldi got ahead 1-2, then unleashed an 80.4 mph curveball that appeared to land right on the corner of the strike zone. Home plate umpire Laz Diaz called it a ball.

Two pitches later, Castro laced an RBI single to center, giving Houston a 3-2 lead. The floodgates would open from there, as the Astros would plate six more runs in the ninth, win, 9-2, and even the ALCS at two games apiece.

If the 1-2 pitch to Castro was called a strike, the Red Sox would have headed to the ninth inning with the score tied and the chance to take a 3-1 series lead on a walk-off. Instead, Diaz’s ball call extended an inning that turned into the worst of the postseason for Boston.

“I thought it was a strike, but, again, I’m in the moment,” Eovaldi said. “I’m trying to make my pitches. I’m attacking the zone."