PEORIA, Ariz. (AP) — James Shields pitched a hitless inning in his Kansas City debut, and the Royalsremained unbeaten this spring with a 5-4 win Thursday over the San Diego Padres.

Shields was acquired in a big trade with Tampa Bay during the offseason. The new ace worked the first inning, then went to the bullpen to reach his pitch count.

The Royals improved to 6-0-1.

Padres starter Jason Marquis also made his spring debut, allowing one hit in two shutout innings. He is expected to be the team's No. 3 starter.

Johnny Giavotella drove in two runs for the Royals. Alexi Amarista hit a two-run double for San Diego.

Padres closer Huston Street pitched his first inning of the spring and gave up two runs and five hits.