Guthrie (14-10) allowed just one run and nine hits, but was helped by three double plays.
Kansas City pulled within three games of a wild-card spot. The Royals also got a game closer to the Indians, who dropped to 6-3 this month.
Mike Moustakas hit a two-run double in the sixth off Zach McAllister (7-9), and the will not-go-away Royals won for the 12th time in 17 games.
Luke Hochevar struck out all five batters he faced, and closer Greg Holland worked a perfect ninth for his 41st save.
TWINS 4, ATHLETICS 3
In Minneapolis, Minnesota, Josh Willingham hit two home runs, including a two-run shot in the eighth inning that put Minnesota in front for good against Oakland.
Oswaldo Arcia also homered for the Twins, who snapped Oakland’s three-game winning streak and prevented the A’s from stretching their two-game lead over Texas in the AL West.
Minnesota also spoiled a solid outing by Jarrod Parker, who tossed six strong innings and stretched his unbeaten streak to 19 starts.
Arcia singled off reliever Sean Doolittle to lead off the eighth. Doolittle struck out Ryan Doumit before being pulled for Ryan Cook (6-4), and Willingham launched a 2-0 pitch an estimated 439 feet into the middle deck for his second multi-homer game this season.
Anthony Swarzak (2-2) worked a scoreless eighth on his 28th birthday. Glen Perkins earned his 34th save in 38 chances.
ANGELS 12, BLUE JAYS 6
In Toronto, Mark Trumbo matched a team record with four extra-base hits, including back-to-back home runs with Josh Hamilton, while Chris Iannetta and Erick Aybar also went deep as Los Angeles beat Toronto.
Trumbo had a career-best five hits and became the first player in Angels history to collect five hits and score five runs in the same game. He went five-for-five with three doubles and two RBIs as the Angels won for the eighth time in 11 meetings with the Blue Jays.
Jerome Williams pitched five-plus innings to win consecutive starts for the first time since May 26. Williams (7-10) allowed six runs and nine hits.
Anthony Gose hit his first career grand slam for the Blue Jays and Rajai Davis added a solo shot, but it was a rough night for starter Mark Buehrle (11-8), who had won six straight decisions.
TIGERS 9, WHITE SOX 1
In Chicago, Rick Porcello pitched his first career complete game, Prince Fielder homered among his four hits and Detroit snapped a three-game skid by beating Chicago.
Alex Avila added four hits and two RBIs as the Tigers increased their AL Central lead over Cleveland to 5.5 games.
Porcello (12-8) scattered seven hits, struck out five and walked one. The 24-year-old right-hander retired 14 straight after Chicago scored their only run in the fourth.
Five of Detroit’s runs were unearned thanks to four Chicago errors, including three by third baseman Conor Gillaspie.
White Sox prospect Erik Johnson (0-2) was hurt by shoddy fielding in his second major league start. He lasted 3-2/3 innings, allowing six runs — two earned — on seven hits and three walks.
Chicago, last in the AL Central, have lost 10 of 12.
ASTROS 13, MARINERS 2
In Seattle, Washington, Jonathan Villar homered on the first pitch of the game and Houston coasted to a lopsided victory over Seattle.