WASHINGTON (AP) The Washington Nationals couldn't have asked to be in a better situation as they attempted to secure their second winning streak since the All-Star break.
Washington built a 4-0 lead against the last-place Colorado Rockies and were in complete control when Drew Storen entered in the eighth inning. Storen, after all, hadn't given up a run in 14 appearances since June 24.
That streak is over. Storen yielded a grand slam to Carlos Gonzalez, and the skidding Nationals lost 5-4 Friday night.
''Storen came out with his best and Cargo came out with his best,'' Washington's Bryce Harper said.
Storen's best wasn't good enough for the Nationals, who have lost six of eight to drop 2 1/2 games behind the first-place New York Mets in the NL East. It was a rare ineffective performance by Washington's former closer, who lost his job when Jonathan Papelbon was obtained in a July 28 trade with Philadelphia.
With two outs, a runner on first and the Nationals ahead 4-1, Jose Reyes and Nolan Arenado singled to load the bases for Gonzalez, who drove a 1-0 pitch into the Washington bullpen beyond the wall in right field. It was only the second home run allowed by Storen (2-1) this season.
''A couple of guys get on base for various reasons and then I make one bad pitch, a fastball over the plate to a very good hitter,'' Storen said.
Since June 1, Gonzalez leads the NL with 19 home runs. This one was particularly enjoyable.
''A big moment. I knew that was the key to the game,'' Gonzalez said. ''Storen has been great the whole season. It was just a rough outing for him.''
Washington wasted a strong outing by Jordan Zimmermann, who allowed one run, four hits and no walks in 6 2-3 innings.
Bryce Harper scored two runs, singled, walked twice and hit a run-scoring grounder for the Nationals. Washington scored in three different innings against Jorge De La Rosa, and Harper was in the middle of each uprising.
One swing by Gonzalez, however, undid the lead that Harper helped build. Washington was 46-3 when ahead after seven innings.
''Drew's been unbelievable all year for us,'' Harper said. ''Nothing you can do about that.''
And, there's little the Nationals can do about this painful defeat expect attempt to regroup over the weekend.
''I guarantee none of the teams in our division feel sorry for us. The Mets are happy,'' said Danny Espinosa, who had two hits and scored twice. ''That's a good team right there. For us, we've just got to keep going, keep plugging and go day-to-day and try to get wins.''
Arenado had three hits and scored twice for the last-place Rockies, who now have their first winning streak since the All-Star break.
Scott Oberg (3-2) pitched a scoreless seventh inning, John Axford worked the eighth and Tommy Kahnle got three outs for his first major league save, striking out Harper to end it.
De La Rosa gave up three earned runs and six hits in six innings. Colorado's career leader in wins (76) has earned only one of them since July 5.
Washington got an unearned run in the first inning. Espinosa doubled, took third when left fielder Kyle Parker misplayed the ball and scored on a groundout by Harper, his first RBI in nine games.
Harper led off the fourth with a single and scored on a double by Ryan Zimmerman for a 2-0 lead.
The Nationals added two runs in the sixth. After Espinosa got an infield hit and Harper walked, Jayson Werth hit a sacrifice fly and Ian Desmond followed with an RBI double.
Colorado finally broke through against Zimmermann in the seventh, when Arenado led off with a double and scored on a two-out single by Ben Paulsen.
Nationals: INF Anthony Rendon was given the day off, a precaution after his recent return from a left quad strain. ''If we push him too hard it can flare up again,'' manager Matt Williams said.
Rockies: RHP Eddie Butler (3-8, 5.45 ERA) faces Washington for the first time on Saturday. He's 0-3 with an 8.41 ERA in four starts since May 30.
Nationals: Stephen Strasburg (5-5, 5.16 ERA) returns from the 15-day DL (oblique) to make his first start since July 4.