CINCINNATI — Colorado turned to an unlikely source to finally get a win in extra innings.

Slumping rookie Dexter Fowler’s two-out RBI triple in the 11th inning off of Nick Masset helped Colorado beat the Cincinnati Reds 6-4 on Sunday and complete a three-game sweep.

‘‘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.

Reds’ boxscore

Sunday’s Game

Rockies 6, Reds 4, 11 innings

Colorado Cincinnati

ab r h bi ab r h bi

S.Smith lf 4 0 1 0 Sutton lf 5 0 2 0

Fowler cf 2 1 1 1 Hanign c 4 0 0 0

Barmes 2b 3 0 0 0 Votto 1b 4 1 1 1

FMorls p 0 0 0 0 BPhllps 2b 5 1 1 0

GAtkns ph 1 0 1 1 Rolen 3b 2 0 0 0

Street p 0 0 0 0 ARosls pr-3b 1 1 0 0

Helton 1b 6 0 1 0 Gomes rf 4 0 0 0

Hawpe rf 4 1 0 0 L.Nix cf 4 1 1 3

Tlwtzk ss 5 2 2 1 AlGnzlz ss 3 0 0 0

Stewart 3b 4 1 2 2 Arroyo p 2 0 0 0

Iannett c 5 1 2 0 Balentn ph 1 0 0 0

CGnzlz cf-lf 3 0 3 0 Rhodes p 0 0 0 0

Marqus p 2 0 0 0 Corder p 0 0 0 0

Splrghs ph 1 0 0 0 HBaily ph 1 0 0 0

RBtncr p 0 0 0 0 Masset p 0 0 0 0

Beimel p 0 0 0 0

Daley p 0 0 0 0

Quntnll 2b 1 0 0 0

Totals 41 6 13 5 Totals 36 4 5 4

Colorado 000 102 010 02 — 6

Cincinnati 000 000 310 00 — 4

E—Ale.Gonzalez (4). DP—Colorado 1, Cincinnati 1. LOB—Colorado 9, Cincinnati 3. 2B—B.Phillips (17). 3B—Fowler (5). HR—Tulowitzki (20), Stewart (18), Votto (17), L.Nix (9). CS—Stewart (3), Sutton (1). S—Barmes, C.Gonzalez, Marquis.

IP H R ER BB SO

Colorado

Marquis 7 4 3 3 2 4

R.Betancourt H,3 2-3 0 0 0 0 1

Beimel BS,5-6 0 1 1 1 0 0

Daley 1 0 0 0 0 1

F.Morales W,3-0 1 1-3 0 0 0 1 1

Street S,28-29 1 0 0 0 0 2

Cincinnati

Arroyo 7 7 3 3 3 1

Rhodes 1 3 1 1 0 1

Cordero 2 0 0 0 1 3

Masset L,4-1 1 3 2 2 0 0

Beimel pitched to 1 batter in the 8th. HBP—by Marquis (Rolen). WP—Masset. Umpires—Home, Paul Nauert; First, Joe West; Second, Ed Rapuano; Third, Paul Schrieber. T—3:29. A—31,142 (42,319).