Detroit – who now lead the Royals by two-and-a-half games ahead of Sunday's final clash between the two sides – won thanks to crucial seventh-inning scores from Victor Martinez and Eugenio Suarez.
Martinez made it a fifth 100-RBI season, and his first since 2011, in the first inning for Detroit, who took the lead in the fourth.
Torii Hunter's home run to left field provided that and although it was short-lived – Jarrod Dyson levelled proceedings in the fifth – the Tigers responded in the fifth.
Singles from Tyler Collins and Rajai Davis led to the double score, meaning that Lane Adams' run in the bottom of the eighth was just a consolation.
Derek Jeter moved into outright ninth on baseball's all-time run list with the 1,920th of his glittering career in the New York Yankees' defeat to the Toronto Blue Jays.
The Blue Jays kept their slim play-off hopes alive with a 6-3 win, made even more impressive by their late rally.
Jeter levelled the score at 1-1 in the third and the Yankees held a 2-1 lead at the bottom of the fifth.
Three runs in the sixth from the Blue Jays changed the game, though, as Jose Bautista, Edwin Encarnacion and Dioner Navarro all scored.
Jerome Williams became the first pitcher in baseball history to post three wins against the same team in one season as a player for three different teams.
Williams beat the Oakland Athletics as a player for the Houston Astros in April and repeated the dose in July with the Texas Rangers.
So there was a sense of deja vu when he threw seven scoreless innings for the Philadelphia Phillies in their 3-0 win over Oakland.
Nick Franklin's first Tampa Bay home run helped the Rays to a 3-1 win against the Chicago White Sox and Adam Jones hit two two-run homers as the Baltimore Orioles toppled the Boston Red Sox 7-2.
Two home runs to Chris Coghlan set up Chicago Cubs' 8-7 thrilling win over the Los Angeles Dodgers, while Tony Cruz' three-run homer triggered the St Louis Cardinals' 8-4 success against the Cincinnati Reds.
Other results saw the Colorado Rockies beat the Arizona Diamondbacks 5-1, while the Astros hammered the Seattle Mariners 10-1 and the Cleveland Indians triumphed 7-3 against the Minnesota Twins.
In closer matches, the Milwaukee Brewers edged the Pittsburgh Pirates 1-0 and the Washington Nationals and San Diego Padres recorded 3-2 wins against the Miami Marlins and San Francisco Giants respectively.
Elsewhere, the Los Angeles Angels beat the Texas Rangers 8-5 and the New York Mets toppled the Atlanta Braves 4-2.