KANSAS CITY, Mo. — The Kansas City Royals cooled off the Oakland Athletics rather quickly.

Mike Sweeney hit a go-ahead, two-run double in a four-run eighth inning, and the Royals beat the A’s, 5-3, on Friday night to complete a doubleheader sweep.

Kansas City won the opener 7-1 as Luke Hudson stymied Oakland on five hits in seven innings. The A’s had just three hits in the second game and nine in the doubleheader.

Coming in, the Athletics had won six straight, 13 of 14 and 17 of 20. Oakland, which began the day with a six-game AL West lead, had won 12 in a row at Kansas City since May 30, 2003, outscoring the Royals 95-30 in that span.

“I don’t know what it is,” Royals manager Buddy Bell said between games. “I don’t think we play any different.”

The Royals last swept a doubleheader Sept. 20, 2005, when they hosted the Detroit Tigers. Oakland played its first doubleheader since June 8, 2003, when it was swept at Philadelphia. The A’s have not swept a twinbill since Aug. 22, 1998, against Detroit.

Giants’ streak continues in L.A.

SAN FRANCISCO — Omar Vizquel and Shea Hillenbrand each hit two-run homers to help Jason Schmidt win his third straight decision, and the San Francisco Giants beat the Los Angeles Dodgers, 7-3, on Friday night for their fifth straight victory.

Steve Finley added a solo homer in the eighth for the Giants, who looked out of contention a week ago but suddenly are playing well again in the crazy, underachieving NL West. San Francisco sent Los Angeles to just its third loss in 20 games on a cool summer night in the Bay Area.

Schmidt (10-7), facing Los Angeles in back-to-back outings, struck out five and pitched into the eighth to beat the Dodgers for the first time in seven starts since a victory on July 14, 2005. He received a no-decision against starter Greg Maddux last Sunday at Dodger Stadium.

Nomar Garciaparra had an RBI groundout and J.D. Drew hit a sacrifice fly for the first-place Dodgers, who began a key nine-game road trip against the division. They have lost two straight games including a 15-4 defeat by the Florida Marlins on Wednesday.

Vizquel homered for the first time in nearly three months when he sent the first pitch from Brad Penny (13-6) into the elevated right-field seats in the third after Randy Winn drew a walk to start the inning. Vizquel’s fourth homer of the year was all it took to bring on the chants of “Beat L.A.! Beat L.A.!” from the sellout crowd of 42,862 in San Francisco’s waterfront ballpark.

Vizquel went 266 at-bats between home runs since connecting off Braden Looper of the St. Louis Cardinals on May 22. Finley homered for the first time since June 25, a span of 118 at-bats.