KANSAS CITY, Mo. -- The Kansas City Royals drafted Andrew Triggs in the 19th round in 2012, but they discarded him in 2015 when they sold his contract to the Baltimore Orioles.

On Wednesday night, Triggs showed the Royals what he can do.

Triggs pitched six scoreless innings, and Jed Lowrie drove in three runs as the Oakland Athletics continued their domination of the Royals with an 8-3 victory.

"The most important thing is to win the series," Triggs said after Oakland won for the second time in the three-game set that ends Thursday.

The A's extended their winning streak to eight over the Royals. They have outscored the Royals 53-15 in winning their past six games at Kauffman Stadium.

"It is a tough team and it's been a tough team for us, so hopefully it continues," Oakland manager Bob Melvin said.

Triggs (2-0) has not allowed an earned run in 11 2/3 innings in his two starts. He yielded four hits, walked one and struck out three in beating the Royals.

"The lights come on and the real games begin, you want to perform," Triggs said.

In a March 27 spring training start against Kansas City, Triggs yielded eight runs on eight hits, including three home runs in 3 2/3 innings. In the rematch when it counted, Triggs was in complete control.

"There's a difference between spring training and the season, but he threw the ball well," Royals manager Ned Yost said.

The A's batted around in a four-run sixth with Lowrie driving in a pair of runs with a bases-loaded double off the right field wall against Chris Young. Rajai Davis and Matt Joyce singled home the other runs in the inning.

Kansas City starter Jason Hammel (0-1) allowed four runs and seven hits in 4 2/3 innings.

The Royals broke a 19-inning scoreless drought with two runs in the eighth off Liam Hendriks. Lorenzo Cain's third hit, an infield single, scored Raul Mondesi with the first run. Eric Hosmer singled home Mike Moustakas with the other run.

Mondesi homered with two out in the ninth for the final Kansas City run.

The A's led 4-0 after five innings.

Davis had an RBI double in the third. Yonder Alonso produced a run-scoring single, and Trevor Plouffe lifted a sacrifice fly in the fourth.

Marcus Semien manufactured a run in the fifth. He led off with a walk, stole second, went to third on a wild pitch and scored on Lowrie's flyout.

The Royals went 2-for-11 with runners in scoring position and are 8-for-52, (.154) with runners in scoring position during their 2-6 start.

"We haven't been very proficient there," Yost said. "We're just not getting it done. You can come up with all the excuses you want, but we're just not getting it done right now."

NOTES: The Royals promoted LHP Scott Alexander and RHP Jake Junis from Triple-A Omaha. Alexander retired all seven A's he faced. Junis made his big league debut and pitched out of a bases-loaded jam in a scoreless ninth. They replaced OF Terrance Gore, who was optioned to Double-A Northwest Arkansas, and LHP Matt Strahm, who was optioned to Triple-A Omaha. ... DH Ryon Healy, who had batted third in seven of the first eight A's games, was dropped to sixth. Healy had two hits and a walk and is hitting .194. ... Alex Gordon played right field for the Royals for the first time since July 27, 2010. It was only his fourth start in right. ... The A's are removing the tarps covering the Oakland Alameda County Coliseum third-deck seats. With more than 12,000 additional seats, that will bring the capacity to 47,170. ... A's RHP Jesse Hahn and Royals LHP Jason Vargas are the Thursday probables.