As expected, Jacob Misiorowski brought some record heat to MLB’s biggest stage.

The Milwaukee Brewers ace fired a 103.5 mph fastball to Tampa Bay Rays leadoff hitter Yandy Díaz to open the 2026 World Series on Friday, the fastest pitch in the recorded history of the Fall Classic according to MLB.com’s Sarah Langs. MLB’s pitch tracking goes back to 2008.

This season has seen Misiorowski enter the record books in a number of ways when it comes to throwing the ball hard. He still hasn’t topped Aroldis Chapman’s overall pitch speed record of 105.9 mph, but he came 0.4 mph short at 105.5 mph in June. That was still the fastest pitch ever thrown by a starting pitcher, and the third-hardest overall.

It also took Misiorowski only one pitch to break the MLB postseason pitch velocity record, as his 104.8 mph fastball to open Game 1 of the NLDS represents the new high watermark.

As impressive as Misiorowski’s fastest pitches have been, where he really stands out in history is how often he is able to hit triple digits. He had 52 pitches faster than 100 mph in Game 1 of the NLDS alone, then 44 in Game 1 of the NLCS. After only five appearances (three starts) in 2025 and 2025, he is already second in MLB history in 100-mph pitches in the postseason.

That velocity translated to historic dominance during the regular season, so much so that Misiorowski is the presumptive Cy Young winner in the National League. However, Misiorowski’s two starts in the postseason before Friday haven’t quite been up to that standard.

The 6-foot-7 right-hander didn’t get past the fifth inning in either start against the San Diego Padres and Los Angeles Dodgers, with both teams finding a way to grind out at-bats in a way few teams did against him during the regular season. After leading MLB in whiff rate on his fastball with a ludicrous 56.3% per Baseball Savant, Misiorowski managed only four such pitches against the Padres and five against the Dodgers.

The Brewers’ World Series hopes may rest on him avoiding a repeat against the Rays.