MINNEAPOLIS — For the past two months, Royals starter Danny Duffy has been lights-out on the road, allowing one earned run or fewer in six straight road starts.

On Sunday, Duffy’s road streak came to a screeching halt as the Twins ambushed him for six earned runs, prompting the Royals’ 6-5 loss at Target Field. The loss was Kansas City’s fourth straight and capped off a series sweep in Minnesota.

Kansas City handed Duffy some early run support when Lucas Duda crushed his 10th homer of the season in the first inning, a two-run shot off of former Royal Ervin Santana. Duda’s long ball left his bat at 104.9 mph and traveled an estimated 431 feet, according to Statcast™.

But Duffy ran into trouble in the second when Miguel Sano and Logan Forsythe each singled to start the inning and Ehire Adrianza later drew a two-out walk to load the bases. Duffy ran Jake Cave up to a full count and nearly escaped the jam, but Cave hammered a 94.8 mph fastball over the right-field wall for a grand slam.

The Twins added to their lead in the fourth when Adrianza delivered an RBI single, and Robbie Grossman later added a run-scoring double to give the Twins a 6-2 advantage.

Duffy exited after the sixth inning having surrendered six earned runs on eight hits, while striking out six Minnesota batters and walking just one. Coming into Sunday, he owned a 2.21 ERA in 20 career appearances against the Twins, the best in the Majors among active pitchers who have thrown at least 100 innings. Sunday marked the 14th straight outing in which Duffy has gone at least five innings.

Royals leadoff man Whit Merrifield cut the Minnesota lead to 6-5 in the seventh inning when he hammered a two-run homer into the Kansas City bullpen. According to Statcast™, the 421-foot shot was Merrifield’s longest homer of the season.

The Royals got the go-ahead run to second base in the eighth when Hunter Dozier came on to pinch-hit for Ryan O’Hearn with two outs. Dozier blooped a single to shallow right field to advance Rosell Herrera to third, and then proceeded to steal second. But Twins reliever Trevor May punched out Alcides Escobar with a high fastball to end the threat.

Kansas City once again put the winning run in scoring position in the ninth, but Minnesota closer Fernando Rodney stranded Adalberto Mondesi at third and Duda at second when he got Herrera to ground out and end the game.