The Royals scored three unearned runs in the seventh to key a comeback 5-4 victory over Boston at Municipal Stadium in Kansas City.

Trailing 4-2 and facing Red Sox starter Sonny Siebert, the Royals began their rally with singles from Lou Piniella and Jerry Adair. Bob Oliver hit a grounder to third, but first baseman Dalton Jones let the throw get away from him. Piniella scored, while pinch-runner Tom Burgmeier reached third and Oliver took second. Two outs later, light-hitting Jackie Hernandez hit a bloop single up the right-field line to drive in two runs and put the Royals in front.

The Royals actually had a 1-0 lead after Mike Fiore two-out home run in the first. But Boston struck back in the third against Royals starter Dick Drago. Siebert drew a walk to start the inning. After a sacrifice bunt, foul out, and walk by Carl Yastrzemski, Reggie Smith homered for a 3-1 Boston lead.

Kansas City got one run back in the bottom of the inning, as Hernandez singled with two outs, moved up to third on Pat Kelly’s double, and scored on a wild pitch. But Fiore grounded out, ending the inning with the tying run still at third.

Yastrzemski doubled in the fifth to drive in one more run, giving Boston that 4-2 lead. But Jones’s key error set up the Royals’ winning rally.

Dave Wickersham worked the final two innings for the save.

The win was the fourth straight for KC and evened the Royals’ record at 21-21. They were in third place in the AL West, 3.5 games behind Minnesota.

Box score and play-by-play:
http://www.baseball-reference.com/boxes/KCA/KCA196905270.shtml

Today’s birthdays: Mike Caruso (1977), Brad Boxberger (1988)