Brett Phillips tied the game with a ninth-inning home run, and Adalberto Mondesi followed two batters later with a go-ahead double as the visiting Kansas City Royals handed the playoff-contending Oakland Athletics a stunning 6-5 defeat Monday.

Jorge Soler bombed his 45th home run for the Royals, whose win trimmed Oakland's lead for the first American League wild card to one game over Tampa Bay and 2 1/2 over Cleveland.

Oakland (90-61) saw its six-game winning streak end.

The Royals' uprising came immediately after Khris Davis broke a 4-4 tie with a run-scoring single in the eighth. Matt Olson began the inning with his second double of the game, and after Mark Canha reached on a fielder's choice, Davis later hit a 3-1 fastball up the middle for a hit.

Phillips' homer, his second of the season, came off A's closer Liam Hendriks (4-3), who is now 22-for-28 on save chances.

Whit Merrifield followed with a fly ball that A's center fielder Ramon Laureano dropped for an error, putting a runner at second. Merrifield raced home on Mondesi's double.

Kevin McCarthy (4-2), who served up Davis' go-ahead single in the eighth, was credited with the win. In the bottom of the ninth, Royals closer Ian Kennedy worked around Marcus Semien's third hit of the game, an infield single, for his 30th save.

Semien had earlier hit his 31st home run, a two-run shot that gave Oakland a 4-1 lead in the second inning. Olson's first double plated the Athletics' first two runs in the first.

Kansas City (56-95) rallied into a 4-4 tie on Soler's homer in the fourth and a two-out, two-run single by Alex Gordon in the fifth.

Gordon's hit came on the sixth pitch from Jake Diekman, who had just replaced A's starter Tanner Roark. The runs were charged to Roark, whose final line was four runs and seven hits allowed in 4 2/3 innings, with one walk and eight strikeouts.

Like Roark, Royals starter Glenn Sparkman did not get a decision. He was pulled after 4 1/3 innings, having allowed four runs and six hits. He walked three and struck out one.

Mondesi finished with three hits, while Merrifield and Soler had two apiece for the Royals.

Laureano joined Semien (three) and Olson (two) in the multiple-hit category for the A's with a pair of singles.

--Field Level Media