(SportsNetwork.com) - Madison Bumgarner will try to get himself and the San Francisco Giants back on track when he takes the mound Sunday in the finale of a three-game series versus the Colorado Rockies at AT&T Park.

The Giants have lost the first two tests of this set and five of six overall.

Bumgarner hopes to change that when he makes his 15th start. He had won three straight trips to the mound and his last six decisions until Tuesday's tough- luck loss to Washington. Bumgarner gave up both runs in the 2-1 setback and lasted seven innings, falling to 8-4 with a 2.67 earned run average.

The left-hander has a 3-3 mark in six home starts and is 8-6 with a 3.26 ERA in 18 career starts against Colorado.

San Francisco blew another lead in Saturday's 5-4 loss, as the Rockies scored two runs in the top of the ninth and Giants closer Sergio Romo suffered the loss. Brandon Barnes hustled for a two-run inside-the-park home run with two out and the Giants never threatened in the bottom half.

"This is a tough one for these guys to lose," said Giants manager Bruce Bochy. "That's a tough way to lose a game but we have to move on and be ready for tomorrow."

Ryan Vogelsong allowed three runs in five innings in the no-decision, while Hunter Pence and Buster Posey each homered and combined for four hits and four RBI.

The NL West-leading Giants will start a five-game trip on Tuesday against the Chicago White Sox and Arizona Diamondbacks.

Rockies reliever Rex Brothers struck out the side in the eighth inning to earn the win, while closer LaTroy Hawkins ended the game with a scoreless ninth to secure his 13th save of the year.

Michael McKenry went 3-for-4 with a run scored and Blackmon, Josh Rutledge and Ryan Wheeler each recorded an RBI for Colorado, which has won four in a row and will visit Los Angeles next for three games. Christian Bergman got the start for the Rockies and gave up three runs in six innings.

Juan Nicasio takes the mound for the Rockies Sunday and is 5-5 with a 5.70 earned run average. He has lost three straight starts, including Tuesday's 13-10 decision to Atlanta in which he was torched for 10 runs and 11 hits in only 3 2/3 innings.

Nicasio has made six career starts against the Giants, going 2-1 with a 2.73 ERA. He is 2-3 in five road starts this season.

Colorado is 6-4 against the Giants this season.