SAN DIEGO – If the Phillies decide to have a fire sale this time next month – a prevailing thought among many, save manager Ruben Amaro Jr. – two of their hottest commodities are the World Series-tested arms of Cliff Lee and Jonathan Papelbon.

Lee would be a certifiable ace to any team with playoff aspirations while Papelbon would be the shutdown closer some contending teams (Detroit? Boston?) desperately need.

But the respective stocks of the two Phillies pitchers are moving in different directions.

While Lee continued his mastery of the National League on Monday night in San Diego, Papelbon coughed up another late lead as the reeling Phillies lost in disastrous fashion a Petco Park.

The ninth inning began with Lee eyeing his second shutout in his last seven games. It ended with a dejected Papelbon walking off the mound after blowing his fourth save in the last eight days.

In the 10th, Kyle Blanks ripped a ball down the third base line off Justin De Fratus to cap San Diego's wild, 4-3, come-from-behind victory. After his team was blanked for the game's first eight innings, Blanks drove in three of the Padres four runs in the final two frames.

"Heartbreaking," De Fratus called the defeat. "Anytime Cliff had a lead you're feeling pretty confident the game is ours. It just fell a part in the end."

Papelbon, who had converted 13 straight save chances to begin the season, has blown 4 of his last 5 save opportunities.

"He's in a little funk," manager Charlie Manuel said. "Things aren't going his way right now."

"It's not any tougher than any other situation I've been in," Papelbon said of his sudden cold spell. "I've been in this situation a million times before. I don't really carry previous ballgames into the next day. It's just not what I do. If you're a closer or relief pitcher or starter, if you take stuff into the next day, it gets out of hand."

The Phillies (36-41) sunk to five games below .500 for the first time since May 10, when they were 16-21.

The farther the Phils move away from being a winning team the more likely Amaro will sell off parts before the July 31 trade deadline. While interest in Papelbon may have cooled off some, Lee continued to look like the apple of the eye of every general manager in baseball.

Long established as a big game pitcher, Lee has become a stopper, too.

When Lee took a 3-0 lead into the ninth inning on Monday, he was in position to lead the Phils to victory for the seventh time in his last 10 starts following a loss.

Lee is 8-0 with a 2.00 in those last 10 starts.

"I don't know what to say," Lee said after Monday's crushing defeat. "I felt like I pitched good and gave us a chance to win and it just didn't happen."

For as easy as he made it look in the game's first eight innings, Lee was hit hard by the only two batters he faced in the ninth. Taking the mound in the ninth with 109 pitches through the first eight, Lee surrendered a single and a double to Carlos Quentin and Chase Headley to begin the ninth.

Enter Papelbon.

Papelbon's second pitch was laced into center field by Blanks for a two-run single, cutting the Phillies lead to 3-2. After hitting a batter, Papelbon induced a double play to move one out away from securing the victory.

But his 2-0 pitch to Mark Kotsay evaded the glove of catcher Carlos Ruiz. The passed ball tied the game.

"I don't have anything to say," Ruiz said of the splitter that got by him. "I expected to catch the ball. I missed it."

"(Stuff) happens," Papelbon said of the game-tying passed ball.

The ninth inning ruined an otherwise brilliant performance from Lee.

He didn't allow a hit until Carlos Quentin singled with two outs in the fourth inning. He didn't allow a base runner to reach scoring position until Yasmani Grandal hit a booming double in the fifth.

Lee struck out the next batter, however, to end the inning.

Although Lee threw 109 pitches in his first eight innings and his spot came up with a runner on second and two outs in the ninth, Manuel decided to stick with his starting pitcher. Papelbon warmed up in the half inning, but wasn't summoned in until Lee gave up consecutive hits to begin the ninth.

"Pap had a lot of work last week and Lee was pitching a good game," Manuel said of the decision. "I was waging a lot of things. But evidently I didn't make the right choice."

While Lee tamed the Padres, the bottom of the order fueled the Phils offense.

John Mayberry Jr., batting seventh and starting in center field in place of Ben Revere, went 3-for-4 with two runs scored and two stolen bases. He entered the night hitless in 10 at-bats over the previous eight days.

Ruiz, hitting behind Mayberry (and Delmon Young) in the eighth spot, also went 3-for-4. Ruiz's two-out single in the second brought Mayberry home with the game's first run.

Mayberry and Ruiz helped the Phils score their second run, too. After Mayberry led off the fifth with a double, Ruiz moved him to third with a single before Jimmy Rollins brought him home with a sacrifice fly.

The Phils scored their third and final run of the night when Chase Utley led off the eighth with a booming, 402-foot solo home run to right-center.

Utley's home run loomed large in the ninth, as the Padres rallied. But one run insurance run wasn't enough to help the Phillies, who have the worst bullpen in baseball (4.67 ERA entering play Monday).