Grandpa Yaz. (Elise Amendola/AP)

Orioles prospect Mike Yastrzemski led off, played center field and went 4 for 5 for the Bowie Baysox on Thursday, a Class AA debut worthy of his famous surname.

“I didn’t expect this at all,” the grandson of Red Sox legend and Hall of Famer Carl Yastrzemski told “To be honest, I figured I would try to play for a while in [Class A] Delmarva, try to make my way to [Class A Advanced] Frederick by the end of the year and maybe play there for the last month. This is a pleasant surprise. … I felt pretty good tonight. I always try to show my worth in the first couple games and try to help the guys win.”

Mike Yastrzemski, 23, was drafted by the Red Sox in 2009 out of high school, but opted to attend Vanderbilt. He hit .322 during his senior season with the Commodores and was selected in the 14th round of the 2013 draft by Baltimore.

“I think if he would have signed with the Red Sox, it would have been too much pressure,” Carl Yastrzemski told after the two were reunited at a Red Sox-Orioles spring training game in March. “He likes the Baltimore organization.”

In 63 games with Low-A Delmarva, Mike Yastrzemski hit .306/.365/.554 with 10 home runs and 44 RBI. He hit .312 in 23 games with Frederick before becoming the first Orioles prospect from the 2013 draft to reach Double-A. MiLB reports that Yastrzemski is one of two minor leaguers with double-digit home runs (11), triples (13), doubles (21) and stolen bases (17) this season. Cubs prospect Arismedy Alcantara, who was promoted to the majors in June, is the other.

One of Yastrzemski’s four hits in Thursday’s 8-6 win over Altoona was a triple. He also scored two runs and made a diving catch.