(My Sportsbook) - The Washington Nationals may own the worst record in baseball, but they were able to take care of the team with the best mark in the National League on Friday. The Chicago Cubs will try to restore order when the two teams resume a three-game series this afternoon at Wrigley Field.

Washington rallied from an early four-run deficit to outslug the Cubs by a 13-5 score in yesterday's opener. Willie Harris homered twice for the Nationals, including a grand slam during a six-run sixth inning that put his club ahead to stay, and finished with six RBI on the day.

Aaron Boone added a pinch-hit three-run double and Ronnie Belliard went 4- for-5 with a homer, two RBI, and three runs scored as the Nationals won for the second straight time following a brutal 12-game losing streak.

Washington's John Lannan (7-12) took advantage of the rare offensive outburst, getting the win despite giving up five runs on seven hits in 6 1/3 innings.

Mark DeRosa had a two-run homer and Derrek Lee a solo shot for the Cubs, whose lead over second-place Milwaukee was trimmed to 4 1/2 games with Friday's setback.

Neal Cotts (0-2) took the loss after serving up Harris' go-ahead grand slam. Chicago starter Jason Marquis was charged with four runs allowed in 5 1/3 innings.

Despite having compiled a poor 46-83 record on the season, the Nationals have won three of their four meetings with Chicago so far in 2008.

Ryan Dempster will attempt to match a career best for victories in a season when the All-Star hurler takes the mound for the Cubs this afternoon. The right-hander ran his record to 14-5 with six outstanding innings to beat Florida last Sunday, with Dempster yielding just two runs and racking up 10 strikeouts.

The British Columbia native, who's limiting opposing hitters to an NL-low .210 average at the plate for the season, won 15 games while with the Marlins in 2001, but had not posted more than 10 victories since until this year's bounce-back campaign.

Dempster's also excelled at home this season, having compiled an impressive 11-2 mark with a 2.76 earned run average in his 15 Wrigley Field starts. Moreover, the 31-year-old is 6-0 with a 3.33 ERA over 19 appearances (11 starts) lifetime against the Washington/Montreal franchise.

Odalis Perez gets the call for Washington today and tries to continue his strong pitching in August. The veteran lefty is 2-1 with a 2.84 ERA in four starts this month and has yielded three or less runs in each of those games.

Perez is coming off a hard-luck defeat to Colorado on Sunday. He allowed three runs -- two earned -- and just four hits over six innings of his club's 7-2 loss to the Rockies.

The 31-year-old does own a 3-1 record with a 3.44 ERA through five previous starts against Chicago, and he's a perfect 3-0 with a 2.45 ERA over three career appearances at Wrigley Field.