The New York Yankees outlasted the Oakland Athletics in 14 innings to stay a game ahead of the Baltimore Orioles in their torrid American League East race on Saturday.
An infield error that enabled Ichiro Suzuki to score gave the Yankees their seventh consecutive win, a hard-earned 10-9 victory that saw New York rally from a four-run deficit in the 13th to keep the game going.
Baltimore stayed in the hunt with a 9-6 12th-inning triumph over the Boston Red Sox for their sixth win in a row and 16th consecutive extra innings victory.
Meanwhile, the Cincinnati Reds, already assured of a play-off spot, became the first Major League Baseball team to clinch a division race when they beat the Los Angeles Dodgers 6-0 to win the National League Central title.
At New York, the Yankees won it when Oakland first baseman Brandon Moss misplayed an Eduardo Nunez ground ball with the bases loaded.
Raul Ibanez's second home run of the day, a two-run shot, sparked the 13th inning comeback, which also featured a run-scoring wild pitch and a sacrifice fly that scored Alex Rodriguez.
Oakland, which earlier missed two scoring chances with the bases loaded, finally broke loose in the top of the 13th on home runs by Jonny Gomes, Yoenis Cespedes and Chris Carter for a 9-5 lead.
But the Yankees answered with four runs of their own to prolong a game that lasted almost six hours.
"When they scored four runs, a lot of fans went home," Ichiro told reporters. "I bet they're shocked to get home and see the score."
At Boston, Jim Thome drove in Adam Jones with a double to deep right field to put Baltimore ahead in the 12th and Endy Chavez and Manny Machado later added run-scoring singles.
The start was the first in eight weeks for the 42-year-old Thome, who had been sidelined by a herniated disk in his neck.
"A lot of guys would have thrown in the towel with some of the issues he had going on," Orioles manager Buck Showalter told reporters.
"But he grinded through it and came back to make a contribution, and I feel really good for him. He means a lot to our club."
At Washington, the Nationals' Gio Gonzalez became the Major Leagues' first 20-game winner of the season with a 10-4 victory over the Milwaukee Brewers.
Gonzalez (20-8) pitched seven innings, striking out five and walking one while giving up three hits and two runs.
The Nationals, with baseball's best record, already are assured of a playoff spot. They lead the Atlanta Braves by six games in the National League East.
Ryan Zimmerman and Ian Desmond each hit three-run homers in the fourth inning as Washington took a 9-0 lead.
Milwaukee, third in the NL's Central Division, had a six-game winning streak snapped.
At Chicago, the reigning World Series champion St Louis Cardinals remained in the running for a National League wild card playoff spot with a 5-4 victory over the Cubs on John Jay's 10th inning run-scoring double.