Johnson made his Major League debut in Sunday's 4-0 loss to the Tigers, giving up one run on one hit in two innings. He pitched the eighth and ninth innings.
Johnson walked his first two batters in the eighth before retiring the next three. He struck out Don Kelly and Austin Jackson to close the inning, drawing a huge ovation from the hometown fans. The right-hander then allowed a solo homer to Miguel Cabrera in the ninth.
"Just walking off the field in the eighth inning, getting the strikeout and getting out of the jam and having the fans get behind me, that was a pretty special moment," Johnson said. "That's something I'll take with me."
Steve's father, Dave, pitched for the Orioles from 1989-91. The pitcher is a Baltimore native.
They became the sixth father-son duo to play for the Orioles.