Pat Burrell belted a two-run homer and Tim Lincecum tossed eight stellar innings as the San Francisco Giants maintained their lead in the National League West with a 2-1 victory over the Colorado Rockies.

Jose Guillen and Cody Ross each recorded a hit for the Giants, who entered with a one-half game division lead over the San Diego Padres, who play later Friday.

Lincecum held Colorado hitless until Seth Smith opened the sixth with a double. Three batters later, Smith scored on a single by Eric Young Jr. to give the Rockies a 1-0 edge.

The lead did not last long, however, as Jhoulys Chacin issued a leadoff walk to Buster Posey before Burrell deposited a 2-1 offering over the left-field wall for his 19th blast of the season and a 2-1 advantage.

The two hits in the sixth were the only ones allowed by Lincecum (15-10), who struck out nine without a walk en route to his fourth win in five decisions. The two-time reigning NL Cy Young Award winner improved to 7-3 on the road this year.

Brian Wilson worked a perfect ninth for his major league-leading 45th save in 49 opportunities.

Chacin (9-10) had his four-game winning streak snapped, yielding two runs and three hits in seven innings. The 22-year old walked three and struck out eight in losing to the Giants for the first time in three decisions this season.

With their fifth consecutive loss, the Rockies fell 4 1/2 games behind the Giants in the NL West.