Griffin, 19, hit a two-strike RBI double off Orioles starting pitcher Kyle Bradish in his first-ever at-bat to put the Pirates up 1-0 in the bottom of the second inning.
He would score from second shortly after on a Jared Triolo single to make it 2-0.
He is the youngest shortstop to make his big league debut since Alex Rodriguez (18). The top prospect recently signed a nine-year, $140 after being called up to the majors on Thursday.
Through five games in Triple-A ball this season, Griffin batted .438 (7-16) with three doubles, one RBI, and three stolen bases. What he did through the minors in 2025, though, is what shot him to the top of the prospect list.
Last season, Griffin played a total of 122 games through Single-A, High-A, and Double-A ball, where he finished with a combined .333 batting average and a .941 OPS with 21 home runs, 94 RBI, and a whopping 65 stolen bases on 78 attempts, also winning the 2025 Minor League Gold Glove Award.
In Spring Training this year, Griffin only hit .171, going 7-for-41 at the plate with four home runs, nine RBI, two walks, 13 strikeouts, and one stolen base.
Should Griffin remain on the team the entire season, Pittsburgh will receive a draft pick through the Prospect Promotion Incentive.