The victory snapped Colorado's two-game skid and marked its first win over Boston in four tries this year.
"It's big for 'Chatty.' It's big for our club," manager Walt Weiss said. "The three guys, [Jhoulys] Chacin, [Jorge] De La Rosa and Chatty, it's nice having those guys in place moving forward.
"Give a lot of credit to 'Chatty' for the improvement, the strides he's made since last year, how far he's come. … We've seen him shut down some of the best lineups in the game this year."
A star of the first half, Chatwood (8-5, 3.15 ERA) looked like his once dominant self in his best outing since a right elbow injury sidelined him for a month at the end of July.
"I think it's just finding a rhythm again," Chatwood said. "You miss a month, it's not easy to get back out there in a big league game and try to pick up where you left off. So it can get frustrating at times, but I feel like today I had a good rhythm and found it again."
Charlie Blackmon was the other star of the show, sending a 1-1 pitch into the right-field seats for the first leadoff homer of his career. Named the National League Player of the Week on Monday, Blackmon is hitting .500 with five doubles, two homers and six RBIs over his past eight games.
With his Coors Field career coming to a close Wednesday, fans serenaded Todd Helton with a standing ovation before each of his at-bats. Helton answered in his first trip to the plate with an RBI single to left that put the Rockies up 2-0 after the first.
"I know it's a season they won't forget, being a part of this with Todd, watching a legend walk away from the game," Weiss said. "Hopefully they watched the way he prepared every day, not only for this season."
In the third, Troy Tulowitzki mashed a hanging John Lackey (10-13) fastball over the center-field fence -- his third homer in four games -- to give Colorado a three-run edge. Left fielder Corey Dickerson added another solo shot in the fourth, as Lackey's ERA fell to 6.39 in two starts at Coors Field.
Dickerson and Blackmon, regular faces in the lineup with a rash of injuries to key players, have shined in the club's final homestand. Like Chatwood, they're playing to make an impression and become regular pieces next year. "It just shows that we can play up here, we can help," Dickerson said. "There's other teams that are watching us also and we just want to display what we can do and help this team."
Chatwood nearly left with the shutout intact, but Will Middlebrooks shot a fly ball to deep right that jumped off Michael Cuddyer's glove. Helton then made a diving save on a liner hit by Jackie Bradley Jr., but Chatwood couldn't hang onto the ball when the first baseman flipped it to him. Chatwood fired a throw home well wide of catcher Jordan Pacheco and into the Red Sox's dugout, as Middlebrooks scored and Bradley cruised into third.
With pinch-hitter Mike Carp batting, a Chatwood curveball slid wide of Pacheco and Bradley raced home. But a nice flip from Pacheco gave Chatwood enough time to tag Bradley out just before his foot crossed home.
"He wasn't afraid," said Red Sox catcher Jarrod Saltalamacchia. "He threw a lot of fastballs. Mixed in that curveball/slider, got a lot of weak contact from us. I don't think we got too many balls -- two or three -- out of the infield. … I felt like we came out a little more aggressive than usual."
Boston's only other sig of offensive life came in the ninth, when Saltalamacchia sent a two-run homer into the Rockies' bullpen off reliever Josh Outman. That put Maneul Corpas on cleanup duty, and he allowed just one more single as three of the Red Sox's seven hits came in the final inning.
DJ LeMahieu lined a two-run single to center in the seventh to give the Rockies some breathing room. Cuddyer, who extended his lead in the National League batting title race to eight points, hit a two-run single into shallow right to make it an 8-1 lead.
It was a prelude for Wednesday, when the fans offer Helton, the face of the franchise for 17 years, a final salute.
"It's been great to see Todd perform like he has on this homestead," Weiss said. "He's really risen to the occasion."