Promoted from Triple-A last week and making just his fourth career start, Montas (2-0) pitched his second straight impressive game to help the A's win a fifth straight on the road.

The 25-year-old rookie, who recorded his first career win in a 2-1 triumph over Arizona on Sunday, was lifted after throwing 99 pitches in eight innings. He allowed seven hits and did not walk a batter, striking out two.

Montas benefitted from double plays in the first, fourth and fifth innings, helping keep the Royals at bay while the Oakland offense teed off on Kansas City starter Ian Kennedy (1-6).

Olson's first homer, a solo shot, opened the scoring in the second inning.

The A's busted the game open in the third, with Kennedy aiding the cause by walking Jed Lowrie with the bases loaded.

Khris Davis followed with a two-run single for a 4-0 lead, before Olson went deep for a second time, a three-run blast that made it a 7-0 game.

It was the third two-homer game in the young career of Olson, whose season total improved to 11.

Fowler added a third A's homer in the inning, his first of the game, to make it a seven-run uprising and an 8-0 lead.

Kennedy was pulled at inning's end, having allowed eight runs and seven hits in three innings. He walked two and struck out three.

The A's tacked on a run in the sixth on a Matt Chapman RBI single and completed the scoring with a seven-run ninth that included Fowler's second homer, a three-run blow that increased his season total to three.

Olson drove in five runs and Fowler four for the A's, whose run total equalled their season-high, set initially against the Los Angeles Dodgers in April.

Olson, Fowler and Jonathan Lucroy had three hits each. Olson and Lucroy scored three times apiece while Davis and Stephen Piscotty collected two RBIs each for Oakland, which was coming off a 4-6 homestand.

Whit Merrifield went 3-for-3 with a double and a hit by pitch for the Royals, who collected eight hits while being shut out for the third time this season.

--Field Level Media