Nationals 4, Rockies 3: Ian Desmond belted a tiebreaking home run in the seventh inning and drove in two runs as host Washington swept struggling Colorado for its fifth straight victory.

Jayson Werth added a two-run shot and has five RBIs in his last two games, and Doug Fister (7-2) improved to 5-0 in his first five starts in a Nationals uniform after yielding three runs in seven innings. Rafael Soriano permitted a walk and bloop single with two outs in the ninth before retiring pinch-hitter Josh Rutledge to earn his 20th save.

Michael McKenry provided the Rockies' offense with his first home run of the season, but couldn't prevent Colorado from losing for the 14th time in 16 games. Rookie Tyler Matzek pitched 6 1/3 innings and allowed three runs while retiring the final eight batters he faced before Matt Belisle (2-4) relieved and promptly yielded Desmond's blast.

Troy Tulowitzki and Corey Dickerson singled to start the Rockies' second inning and two batters later, McKenry belted a 1-0 pitch over the wall in left. Anthony Rendon led off the Washington fourth with a single and Werth followed by crushing a 3-1 pitch out to left-center before Bryce Harper doubled with two outs and scored on Desmond's single.

Matzek recorded six strikeouts - including the final three batters he faced, but was lifted after fanning Harper to start the seventh. Desmond blasted Belisle's 0-1 offering over the wall in right-center, but his 15th home run was originally ruled not to have left the park until a replay review revealed the ball struck a railing beyond the fence.

GAME NOTEBOOK: Desmond has seven go-ahead home runs this season. ... Colorado, which capped a 1-6 road trip and has lost nine of its last 10 away from home, leads the National League with 100 home runs. .... Colorado acquired RHP Jair Jurrjens, a former National League All-Star with Atlanta who was pitching in Triple-A, from Cincinnati for Double-A 1B Harold Riggins.