CINCINNATI -- Colorado turned to an unlikely source to finally get a win in extra innings.
"I was just looking for a pitch over the plate," said Fowler, who entered the game on defense in the seventh inning and struck out in the ninth. "He throws hard, and I'd never faced him before."
Garrett Atkins added a pinch-hit infield single to help Colorado earn its first win in five extra-inning games this season, all on the road.
The Rockies extended their winning streak to four games, their longest since winning four straight from July 6 through July 9, and sent the Reds to their sixth consecutive loss and 12th in their last 13 games.
"That was a great game to grind that out in the manner in which we did," Colorado manager Jim Tracy said. "We win that game because of several little things that we pride ourselves in."
Chris Iannetta led off the 11th against Masset (4-1) with a single through the hole into left field and reached second on a wild pitch. Two outs later, Fowler lined his triple to deep left-center field.
Fowler, who has started 79 games but had gone 3-for-14 in the first seven games of Colorado's road trip, got the day off on Saturday.
"I take days off in stride," Fowler said. "I try to stay in the game mentally."
"Fowler is doing a wonderful job in his first full season in the major leagues after not having seen a pitch at Triple A," Tracy said. "You have to understand. On any given day, when your name gets called, you have to be ready."
Franklin Morales (3-0) pitched 1 1/3 innings for the win. Huston Street pitched the 11th for his league-leading 28th save of the season. The Reds got their leadoff runner on base in the 10th against Morales, but pinch-hitting pitcher Homer Bailey fouled a two-strike bunt for a strikeout, and Drew Sutton hit into a double play. Bailey pinch-hit because Willy Taveras was not available due to a sore left wrist.
To manager Dusty Baker, it was just more of the same problems that have plagued the Reds for more than a month.
"We fought back, but we didn't get the bunt down and they did," he said.
Colorado starter Jason Marquis allowed two hits over six scoreless innings before giving up Laynce Nix's three-run, game-tying homer in the seventh. The right-hander allowed four hits with two walks and four strikeouts.
Cincinnati starter Bronson Arroyo left with no-decision after allowing seven hits and three runs with three walks and a strikeout in seven innings.
"We're finding ways to lose all the time," Arroyo said. "It keeps snowballing. We get a lead, and we give it up. We fall behind, and we can't come back. We're definitely sliding downhill. It's got to stop at some point."
Ian Stewart opened the scoring with a solo home run with two outs in the fourth inning. It was his 18th homer of the season and first in 37 at-bats since July 19 at San Diego.
The Rockies took advantage of a Cincinnati error while taking a 3-0 in the sixth. With Brad Hawpe on second and Troy Tulowitzki on first, Stewart singled to center to drive in Hawpe with Tulowitzki advancing to third. Tulowitzki scored when shortstop Alex Gonzalez misplayed Nix's throw back to the infield.
"He probably catches that ball 99 times out of 100," Baker said. "That was a big run."
The Reds tied the score in the seventh. Phillips led off with a double up the gap in right-center field and Scott Rolen was hit by a pitch. Jonny Gomes flied out to right field, but Nix hit his ninth home run of the season and first in 45 at bats since July 10 against the Mets at New York.
Colorado regained the lead on Tulowitzki's 20th homer of the season, an opposite-field solo shot off of left-hander Arthur Rhodes in the eighth, but Joey Votto tied the score with his 17th homer of the season and second of the series.
Rolen, in his second game with Cincinnati after being acquired Friday in a trade, left the game after getting hit in the batting helmet. He never lost consciousness and walked off on his own after less than a minute. ... The Rockies also swept the Reds in a three-game series in Cincinnati last season.