Milwaukee Brewers ace Jacob Misiorowski set a historic velocity mark on his very first pitch of the 2026 World Series. On Friday, in Game 1 of the Fall Classic, Misiorowski delivered a 103.5 mph fastball to Tampa Bay Rays first baseman Yandy Diaz, establishing a new record for the fastest pitch in the pitch-tracking era, which began in 2008.
The pitch, which was taken for a ball outside the strike zone, was registered at 103.4 mph on the stadium scoreboards but officially clocked at 103.5 mph by MLB's Statcast system. This surpassed the previous record of 103.2 mph set by Aroldis Chapman in Game 2 of the 2016 World Series.
Misiorowski demonstrated a heavy reliance on his fastball in the opening inning, throwing it for 10 of his first 10 pitches and 11 of 13 pitches overall in the frame. His average fastball velocity during that inning was an impressive 101.9 mph.
Throughout the regular season, Misiorowski has gained attention for his exceptional velocity, throwing 1,115 pitches exceeding 100 mph. This high-octane approach has contributed to his success, as he led the league with a 1.80 ERA and 252 strikeouts over 30 starts, finishing with a 16-5 record. He continued his strong postseason performance in Game 1, recording three strikeouts and allowing one earned run through five innings pitched.
Heading into Friday's game, Misiorowski had a 3.24 ERA with 11 strikeouts in 8 ⅓ innings across two postseason starts. He previously commented on the difference in pressure between starting a postseason game and pitching in relief, a role he fulfilled in the 2025 postseason.
"I think it’s different just the fact that I’m starting, that nerve of actually having the whole game and it being behind me, and it’s kind of different," Misiorowski said after a prior start. "Coming out of the bullpen, you’re like, you get thrown in a situation, it’s unknown. So this one’s a little different.
Nerves are a little higher with the start, so nothing crazy, but that’s about it."