The Chicago White Sox moved to the top of the American League Central standings and strengthened at third base by acquiring Kevin Youkilis from the Boston Red Sox.
Youkilis, who has been supplanted by rookie Will Middlebrooks at Boston, arrives at US Cellular Field in a trade which saw Brent Lillibridge and pitching prospect Zach Stewart move the other way.
And Youkilis' new employers won their series against the Milwaukee Brewers after a 1-0 victory in 10 innings tonight - an exact mirror-image of the Brewers' win in the series opener on Friday.
Eduardo Escobar scored Alejandro De Aza on a game-winning single which took them ahead of the Cleveland Indians in the division standings after the latter lost 7-1 to the Houston Astros.
Chris Johnson batted in three runs including a two-run homer, while JA Happ allowed just four hits in seven innings.
The Detroit Tigers closed on the beaten Indians with a 3-2 win over the Pittsburgh Penguins, Justin Verlander throwing a five-hit complete game.
The New York Yankees edged the Subway Series against city rivals the Mets with a 6-5 win tonight on Robinson Cano's go-ahead homer in the eighth.
Nick Swisher, who earlier hit a three-run long ball, used the aftermath of the game to hit back at Mets reliever Frank Francisco.
"Not too bad for a bunch of chickens," Swisher told ESPN, recalling Francisco's description of the Yankees ahead of the series.
The Yankees' AL East rivals enjoyed a profitable night, with the second-placed Baltimore Orioles beating the Washington Nationals 2-1 as Matt Wieters hit a two-run homer and then threw out Ian Desmond to seal victory.
The third-placed Tampa Bay Rays won both games of their double-header with the Philadelphia Phillies, which came about after Friday's scheduled series opener was rained off.
Carlos Pena's three-run homer earned a 3-2 win in the first game and the second finished 7-3, Brooks Conrad hitting two two-run doubles to complete the sweep.
The St Louis Cardinals moved within two games of the National League Central summit with an 11-8 win over the Kansas City Royals, as the division leading Cincinnati Reds were beaten.
Josh Willingham's two-run shot lifted the Minnesota Twins to a 4-3 win over the Reds and with second-placed Pittsburgh also losing, St Louis took full advantage as a three-run homer from Carlos Beltran set the tone in the first inning.
Matt Holliday and Allen Craig each drove in two runs to take the Cardinals' total to 30 in the course of a three-game sweep.
The Los Angeles Angels won 5-3 in their rubber game against city rivals the Dodgers, Mark Trumbo scoring Albert Pujols for the go-ahead run in the seventh.
That saw the Angels keep pace with the Texas Rangers, who beat the Colorado Rockies 4-2 thanks to Leonys Martin's first three Major League RBIs.
The Dodgers remained three games clear of the San Francisco Giants, who lost 4-2 to the Oakland Athletics.
Elsewhere, the Red Sox beat the Atlanta Braves 9-4, the Miami Marlins staved off a series sweep with a 9-0 rout of the Toronto Blue Jays, the Arizona Diamondbacks beat the Chicago Cubs 5-1 for a sweep and the San Diego Padres beat the Seattle Mariners 2-0.