Philadelphia (39-36) at Atlanta (37-40)

With their once-dynamic lineup scuffling and their ace in a funk, the Philadelphia Phillies are clinging to the smallest possible lead in the NL East.

They probably never figured to be turning to J.A. Happ(notes) for stability.

Coming off his first major league shutout, Happ will get the start Thursday night against the Atlanta Braves, hoping to help the defending champions avoid their first three-game sweep at Turner Field in more than four years.

The Phillies have dropped 13 of their last 17, and there were few positive signs on Wednesday. NL championship series and World Series MVP Cole Hamels(notes) failed to get through five innings for his second straight start and Philadelphia didn’t manage a hit until the seventh inning of an 11-1 loss.

“They took it to us,” Phillies manager Charlie Manuel said. “We got beat bad.”

Much of the slump coincides with slugger Raul Ibanez’s(notes) stint on the disabled list. Philadelphia’s lineup has been inconsistent without him, scoring two or fewer runs five times in the last 11 contests.

Ibanez has hit 22 of the Phillies’ NL-leading 107 homers.

The Phillies (39-36) have won the NL East each of the last two years, but their current lead has slipped to one-half game over second-place Florida. A loss Thursday would mark Philadelphia’s first three-game sweep in Atlanta since April 22-24, 2005 and drop it into a virtual tie with the idle Marlins.

The New York Mets are two games back and Atlanta (37-40) is within three games of the top of the crowded division. The Braves are 6-2 against the Phillies in 2009 after going 4-14 last year.

“Whenever the Phillies are playing against us, we want to let them know that we are here and we’re going to fight for that division,” infielder Martin Prado(notes) told the Braves’ official Web site. “It’s not going to be easy for them.”

Another Atlanta win will be difficult, however, if Happ (5-0, 3.00 ERA) pitches like he did Saturday in Toronto. The left-hander allowed five hits and no walks, needing just 100 pitches to complete a 10-0 win.

“It all kind of came together,” said Happ, 3-0 with a 3.25 ERA in seven starts after beginning the season in the bullpen.

He made two starts against the Braves in September, allowing two runs and eight hits in 12 2-3 innings, and earned a decision with six shutout frames on Sept. 17 during a 6-1 victory in Atlanta.

The Braves are looking for their fourth straight triumph and will counter with Javier Vazquez(notes) (5-7, 3.04), who ranks among the top 10 in the NL in ERA, but has had trouble with run support at times.

He took a tough 1-0 loss against Boston on Saturday after pitching 7 2-3 strong innings with eight strikeouts. In his last seven starts, the right-hander is 1-4 with a 2.61 ERA, but has gotten only nine runs to work with.

“You’ve got too keep battling,” said Vazquez, who is 1-0 with a 3.29 ERA in two starts against the Phillies this year.