Kansas City's won back-to-back games to climb back to one game under .500 (16-17) and take the three-game series from San Diego.
Hosmer led off the 11th Tuesday with a double, and eventually scored the go-ahead run on an Alex Gordon hit. The first baseman didn't wait that long in the third game against its National League opponent.
He picked up two RBIs in the first on a single to center, and later scored on a Danny Valencia hit. Kansas City led 3-0 after the first.
Hosmer came back around with run-scoring hits in the sixth and the eighth. He finished the day 3-4 at the plate with four RBI and a run scored.
It was plenty of run support for James Shields. The Royals ace didn't allow a run and struck out four through seven innings of work to improve his record to 4-3.
Kansas City's west coast swing continues Thursday as they begin a four-game set against the Mariners in Seattle.