MLB: Chicago Cubs 6, Washington 5

WASHINGTON, July 18 (UPI) -- Alfonso Soriano hit a key three-run homer Saturday, boosting the Chicago Cubs to a 6-5 win over Washington.

Soriano's 15th homer this season gave Chicago a 5-4 lead with one out in the sixth. Ryan Theriot hit an RBI triple and a solo homer and Mike Fontenot had two hits and one RBI for the Cubs, who go for a three-game sweep Sunday.

Winner Randy Wells (5-4) yielded four runs and seven hits in five innings.

Closer Kevin Gregg recorded his 18th save with a 1-2-3 ninth.

Washington's Ryan Zimmerman hit two sacrifice flies. Nick Johnson and Nyjer Morgan had three hits and one RBI apiece, while Adam Dunn had one RBI for the Nationals, who have lost three in a row.

Losing pitcher Jordan Zimmermann (3-5) gave up five runs and six hits in 5 1/3 innings with a walk and eight strikeouts.