The highly touted southpaw has yet to pitch above Class A in 28 appearances as a professional, but if he was nervous at the thought of facing big league hitters in his Spring Training debut Sunday, he didn't show it.
Skaggs threw three innings of scoreless relief against the A's, striking out four and allowing a pair of hits as the D-backs rallied for a 4-2 victory at Phoenix Municipal Stadium.
The 19-year-old retired the side in order in the seventh, striking out Kurt Suzuki and Josh Willingham to end the inning.
Skaggs got former World Series MVP Hideki Matsui to fly out leading off the eighth, but Kevin Kouzmanoff doubled to right field. Working out of the stretch for the first time, the 2010 Midwest League All-Star retired Conor Jackson and Michael Taylor to leave the runner in scoring position.
The D-backs plated three runs in the top of the ninth to grab a 4-2 lead, and Skaggs closed out the game for his first Cactus League victory. He fanned Wes Timmons and former No. 1 pick Michael Choice before surrendering a single. But the California native retired Anthony Recker on a game-ending groundout.
Selected 40th overall by the Angels in the 2009 Draft, Skaggs went 8-4 with a 3.61 ERA in 19 appearances for Cedar Rapids in 2010 before the late-season trade to the D-backs.
"Tyler is a high upside, very projectable young left-hander who we feel very strongly about his future," then-interim general manager Jerry Dipoto told MLB.com after the move.
"He was a guy we definitely wanted. It took a year, but now we got him."
Skaggs finished last season with Class A South Bend, going 1-1 with a 1.69 ERA in four starts. Between the two stops, he recorded 102 strikeouts over 98 1/3 innings.
Ranked as the D-backs' No. 2 prospect behind right-hander Jarrod Parker, Skaggs likely will start the season at Class A Advanced Visalia.