The battle for the American League East took another twist as the Baltimore Orioles again closed to within two games of the New York Yankees.
Baltimore had won the first game of the series 6-1 on Friday, only for the Yankees to edge three games clear once more with a 4-3 win in the Bronx on Saturday.
However, the visiting Orioles had the last laugh of the weekend with an 8-3 win on Sunday as Mark Reynolds hit a three-run shot in the sixth inning.
The Yankees had a 10-game lead on July 18 but have won just 19 of their 42 games since, while the Orioles have won 19 of their last 27.
Things are even closer in the AL Central after the Detroit Tigers beat the Chicago White Sox 4-2 to claim a share of first place.
Alejandro De Aza hit Justin Verlander's second pitch of the night over the wall in right field, but the Detroit pitcher was outstanding after that, allowing just four hits in eight innings as his side swept the three-game series.
There were no such problems for AL West leaders the Texas Rangers, who beat the Cleveland Indians 8-3 as 19-year-old Jurickson Profar hit a home run in his first major league at-bat.
National League East leaders the Washington Nationals enjoyed a more narrow 4-3 success over the St Louis Cardinals, while the Atlanta Braves boosted their wild card hopes with an 8-7 victory against the Philadelphia Phillies.
The NL West-leading San Francisco Giants beat the Chicago Cubs 7-5, while the Central-leading Cincinnati Reds saw off the Houston Astros 5-3.
Elsewhere, the Colorado Rockies edged a high-scoring contest with the San Diego Padres 11-10, while Tony Abreu drove in three runs as the Kansas City Royals beat the Minnesota Twins 6-4 to avoid a three-game sweep.
The Los Angeles Dodgers beat the Arizona Diamondbacks 5-4, while Ryan Braun hit an NL-leading 37th home run as the Milwaukee Brewers overcame the Pittsburgh Pirates 12-8.
The Oakland Athletics (76-57) recorded their ninth straight win with a 6-2 victory against the Boston Red Sox, moving into a tie with the New York Yankees for the second-best record in the American League.
The Seattle Mariners beat the Los Angeles Angels 2-1, the Tampa Bay Rays won 9-4 against the Toronto Blue Jays and the New York Mets completed a series sweep with a 5-1 victory over the Miami Marlins.