Chatwood pitched effectively for seven innings, and Charlie Blackmon hit his first career leadoff homer, lifting the Colorado Rockies to an 8-3 victory over the Boston Red Sox on Tuesday night.

“This was one of his best outings, right up there, and he just did that against probably the best offensive ballclub in baseball,” Rockies’ manager Walt Weiss said. “It was quite a performance by him.”

Chatwood (8-5), who established himself as a fixture in the rotation after coming on in late April as an injury replacement, allowed one unearned run and three hits. He walked one and struck out two in his best outing since returning earlier this month from a tender elbow that sidelined him for four weeks.

“I think it’s just finding a rhythm again,” Chatwood said. “You miss a month and it’s not easy to get back out there in a big league game and try to pick up where you left off. It can get frustrating at times, but (Tuesday) I feel like I had a good rhythm and found it again.”

His Boston counterpart, John Lackey (10-13), struggled on the road again, allowing four runs and six hits in six innings. The right-hander is 1-5 away from Fenway Park since the All-Star break.

Lackey also gave up solo homers to Troy Tulowitzki and Corey Dickerson.

The Rockies added four runs in the bottom of the seventh to seal the win, with DJ LeMahieu and Michael Cuddyer delivering two-run singles.

Cuddyer finished 2-for-4 with a double to raise his average to an NL-best .335.

Weiss indicated that Chatwood would make one more start in Sunday’s final game of the season at the Los Angeles Dodgers, and he looked forward to seeing him pitch regularly next season.

“The three guys, Jhoulys Chacin, Jorge De la Rosa and Chatty, it’s nice having that in place going forward,” Weiss said. “Give a lot of credit to Chatty for the improvement, the strides he’s made – pretty incredible, how far he’s come.”