In a losing effort, Detroit's Prince Fielder had two of the Tigers' five hits and knocked in four of their five runs.
Fielder got the Tigers started in the right direction with a two-run double in the first and belted his 12 homer of the season in the top of the fourth for a 3-1 lead, but the Rangers rallied for four runs in the bottom of the frame and were never headed thereafter. Fielder added his fourth RBI on a ground out in the eighth.
Winners of eight of their last 10, the Rangers maintained their 4 1/2 game lead in the AL West over the pursuing Angels, while the Tigers dropped a game to the White Sox in the Central, where they trail by three games.
The series concludes Wednesday night in Arlington, Texas.
Ian Desmond doubled three times and singled in five at-bats, scoring once and driving in a pair of runs, while Michael Morse also went 4-for-5, with a double, three singles, two runs and two RBI.
Adam LaRoche, who's been the teams most consistent power hitter, touched off a pair of homers, drove in three runs and scored three times. LaRoche's homers were his 11th and 12th of the season and upped his team-leading RBI total to 47, tying him for fifth in the league with four other players.
The Nationals continue to lead the NL East by 3 1/2 over Atlanta and evened their four-game series in Colorado at a game apiece with the win.
Despite being third in the league in batting with a team average of .267, the Rockies continue to be plagued by poor pitching. Their team ERA of 5.38 is the worst in either league and their 770 hits allowed are easily tops in the National League. The Milwaukee Brewers are a distant second, having given up 690 hits.
At 28-45, the Rockies are 14 games behind the Dodgers in the NL West. Los Angeles holds a one game lead over the Giants after losing their second straight to their northern rivals, 2-0.