Misiorowski Sets Record with 103.5 mph First Pitch in World Series Debut Brewers starter Jacob Misiorowski threw the fastest recorded World Series pitch on his first delivery of Game 1, a 103.5 mph fastball to Rays first baseman Yandy Diaz. The 24-year-old right-hander also led MLB with a 1.80 ERA and 252 strikeouts in the regular season. Milwaukee Brewers right-hander Jacob Misiorowski made World Series history on his very first pitch of Game 1 against the Tampa Bay Rays on Friday night at American Family Field. The 24-year-old fired a 103.5 mph fastball to Rays first baseman Yandy Diaz, setting the record for the fastest World Series pitch in the pitch-tracking era, which began in 2008. Diaz took the pitch for a ball above the strike zone. The pitch was listed at 103.4 mph on the stadium scoreboards, but MLB Statcast clocked it at 103.5 mph.Chapman held previous World Series recordThe previous record of 103.2 mph was thrown by left-hander Aroldis Chapman of the Cubs during Game 2 of the 2016 World Series. That pitch resulted in a groundout by Cleveland outfielder Coco Crisp. Misiorowski was fastball-heavy in the first inning, starting the game with 10 consecutive fastballs and throwing the pitch on 11 of his 13 offerings in the frame. He averaged 101.9 mph on his fastball during the inning.Heading into the World Series, the record for the fastest pitch thrown by a starting pitcher was 101 mph. Misiorowski broke that mark with his first pitch and tossed a scoreless first inning in Milwaukee's first World Series game since 1982. Misiorowski set the record for the fastest pitch thrown by a starter in recorded Major League Baseball history earlier this season. He has made waves across the league in his first full season for his incredible velocity.He threw 1,115 pitches over 100 mph during the regular season. That high velocity translated into major success. He led the league with a 1.80 ERA and 252 strikeouts while posting a 16-5 record in 30 starts. In 2025, Misiorowski made just 15 appearances in the majors and had a 4.36 ERA.Misiorowski secures best season in franchise historyHe broke onto the scene and earned an All-Star nod, but ran out of gas down the stretch and his role going into the postseason was not clear. This year, he has started Game 1 of the NLDS, NLCS and now the World Series. He has carried the load in the rotation and put together the single best season by a starting pitcher in Brewers history.In the postseason this year, Misiorowski has pitched to a 3.24 ERA with 11 strikeouts in 8 and one-third innings over two starts. Following his start earlier this month in Game 1 of the NLCS against the Dodgers, he discussed the pressure of starting a postseason game compared to coming out of the bullpen, which he did in the 2025 postseason.I think it is different just the fact that I am starting, that nerve of actually having the whole game and it being behind me, and it is kind of different, he said during an appearance on FOX Sports after the game. Coming out of the bullpen, you are like, you get thrown in a situation, it is unknown. So this one is a little different. There were plenty of emotions in American Family Field on Friday night.Starting pitcher displays unmatched firepower on moundThe right-hander did not feed into it, though. He stepped up to the mound and looked like he had done it a million times. We have never seen a starting pitcher with the firepower that he has, one observer noted. He has completely rewritten the record book when it comes to velocity for a starter and he is just getting started.The series has just begun and Misiorowski already has put his name in the record books. There surely will be more coming for the young Brewers starter.