Sean Manaea pitched effectively into the eighth inning and closer Blake Treinen got the final five outs for Oakland, which took three of four in the series after winning two of three in Kansas City a week earlier.

With the score tied at 2-2, Whit Merrifield's second double of the game put the potential go-ahead run on second base for the Royals with no outs in the top of the eighth.

After an infield out advanced the runner to third, Salvador Perez hit a one-hop shot that appeared to be headed through a drawn-in infield. But Semien dove to his right, fielded the ball cleanly and fired home without ever regaining his feet.

The one-hop throw was perfect and nailed a sliding Merrifield by a matter of inches.

Treinen then got Hunter Dozier to ground out to end the inning, setting the stage for Chapman's solo shot to left field leading off the last of the eighth against Royals reliever Jason Adam (0-1).

The homer was Chapman's 10th of the season, the hit his seventh in the four-game series.

Treinen (3-1) allowed a one-out double to Alex Gordon in the ninth, but secured the win by getting Alcides Escobar to ground out, advancing Gordon to third, before retiring Drew Butera on a pop fly.

Neither starter got a decision.

Manaea allowed six hits and two runs in his 7 1/3 innings. He struck out six and did not walk a batter.

Royals rookie Brad Keller, making just his third major league start, was pulled one out into the sixth inning, having given up two runs and five hits. He walked four and struck out four.

Chapman scored one of Oakland's two runs off Keller in the second inning after leading off the inning with a walk. A double by Mark Canha set up an RBI infield out by Stephen Piscotty and run-scoring single by Jonathan Lucroy for a 2-0 lead.

The Royals got even in the third after Merrifield's first double. He scored on a wild pitch, after which Perez smacked his 11th homer of the year, a solo shot that made it 2-2.

Both teams finished with seven hits.

--Field Level Media