DENVER (AP) -- The Colorado Rockies stumbled home this weekend after a 1-9 road trip. After sweeping one of the best teams in baseball, they're feeling good again.
Nolan Arenado hit a go-ahead double in the seventh inning and the Rockies beat Pittsburgh 3-2 Sunday for a three-game sweep of the NL Central-leading Pirates.
The Pirates came to Coors Field this weekend with a five-game winning streak. They hold a three-game edge over St. Louis, and visit the Cardinals for a three-game series starting Tuesday night.
''We pack it up and we go,'' Pittsburgh manager Clint Hurdle said. ''You honestly self-evaluate and move on and get ready to play in St. Louis.''
Pedro Alvarez homered for the Pirates.
The Rockies last swept a series April 16-18 against the Mets on their way to a 13-4 start. They have struggled the last two months to fall from the top of the NL West to out of the playoff race.
They bottomed out with their worst road trip since 2007 but bounced back against the streaking Pirates. Rookie Chad Bettis held Pittsburgh in check to keep his team in the game, and Arenado delivered with two outs and the score tied at 2.
''As quickly as it can go sour, you've got to believe you can turn it around quickly. I'm proud of our guys,'' Colorado manager Walt Weiss said. ''We swept a series against one of the best teams in the game and one of the best pitching staffs.''
With two outs in the seventh, Wilin Rosario singled off reliever Bryan Morris (5-5). Arenado then doubled down the right-field line to score Rosario from first.
''I was looking for cutter or slider middle-away. He threw me a first-pitch fastball in,'' Arenado said. ''If he would have thrown it again I could've been jammed or not swung. Luckily it was a cutter right over the plate and I was able to put a good swing on it.''
Matt Belisle pitched a perfect eighth before giving way to Rex Brothers, who worked a shaky ninth for his 10th save in 11 chances.
Neil Walker singled to start the ninth and one out later Tony Sanchez doubled to right-center to put runners on second and third. Weiss went to the mound for a strategy session before pinch-hitter Jordy Mercer stepped into the box.
''He had a good look in his eye when I went out there,'' Weiss said of Brothers. ''He wanted to go after Mercer.''
Brothers got Mercer on a soft liner to third, and after intentionally walking Gaby Sanchez to load the bases, Alex Presley popped out to third to end the game.
Pittsburgh was swept in a series for the first time since June 3-5 at Atlanta.
Alvarez showed no ill effects from taking a spike to his mitt from Dexter Fowler on Saturday. Alvarez hit the first pitch he saw from Bettis to give the Pirates a 1-0 lead in the second inning. It was his NL-leading 28th home run of the season.
Andrew McCutchen drove in Clint Barmes with an infield single in the third to make it 2-0.
The Rockies made it 2-1 in bottom of the inning when Charlie Blackmon scored on a sacrifice fly by DJ LeMahieu. They tied it in the sixth when Yorvit Torrealba scored on Alvarez's throwing error at third base.
The error spoiled a solid outing and took a potential win away from Jeff Locke. The lefty allowed two runs - one earned - on three hits, struck out three and walked four in 5 2-3 innings. He left after Blackmon's infield single that put runners at first and second with two outs.
Locke was hoping to give his team a win heading into the series with the Cardinals, who will be looking for payback after losing four of five in Pittsburgh two weeks ago.
''You just come into the off-day and everybody can relax and wash this one away,'' Locke said. ''There's a lot of anticipation coming into the Cardinals series. Everybody's excited, everybody's ready to go, so I know it will be a challenge. I don't assume it's going to go the same way it went last time when they came to our place.''
Bettis had a better showing in his second career start, allowing just two runs on four hits and striking out three in six innings. The rookie dropped his ERA from 6.30 to 5.06 Sunday.
He missed out on his first major league win. Manuel Corpas (2-2) pitched a clean seventh inning to get the victory.
NOTES: Alvarez's home run was his first since July 29. ... Rockies OF Michael Cuddyer did not play due to illness. ... Pirates LF Starling Marte was not in the lineup after getting hit with a pitch and having a bruised left hand. He came in as a pinch-runner in the top of the ninth. ... With the Pirates off Monday, rookie RHP Gerrit Cole will have his next start pushed back to Friday against Arizona as the Pirates monitor his innings. ... Pirates RHP Charlie Morton (4-3) will start the opener of a three-game series against the Cardinals. ... Colorado's Jhoulys Chacin (10-5) will start Monday's game against San Diego.