PHILADELPHIA -- The long-awaited return of Bryce Harper figured to give a lift to a Washington Nationals team counting down the days until the postseason begins.

Phillies pitcher Jake Thompson and his bullpen mates had other ideas.

Thompson allowed one run in five-plus innings and Philadelphia's relief corps shut down the Nationals to help the Phillies score a 4-1 victory Tuesday night at Citizens Bank Park.

The Phillies (63-95), who have four games remaining, will avoid becoming the franchise's first 100-loss club since 1961.

"First of all, when I said that 98, 99 or 100 losses didn't matter, I lied," Phillies manager Pete Mackanin said. "I admit it. Great win."

Washington (95-62), meanwhile, has five more opportunities to get three wins to tie its franchise record.

Philadelphia pitching made getting closer to that number almost impossible Tuesday.

Thompson (3-2) hit Anthony Rendon to start the sixth inning and was removed. He allowed four hits and struck out five. Thompson finished the year allowing two runs over his final 15 1/3 innings across three starts.

"It's always good to just give up one run against that lineup," Thompson said. "Just look at it and there's a lot of proven hitters in that lineup.

"I struggled for most of the season. I like to think my stretch up here was quality. I want to go into the offseason, improve on some things and get back here next year."

Thompson exited with a 3-1 lead thanks to a three-run Phillies third inning that featured an RBI single from Tommy Joseph and a two-run double off the bat of Cameron Rupp.

That inning spoiled Washington starter Gio Gonzalez's night. Gonzalez (15-8) allowed those three runs and five hits over five innings. He struck out seven but walked five.

Philadelphia's bullpen, a big reason the Phillies have seen more success in the second half of the season, had four members toss four no-hit, scoreless innings against Washington while striking out nine. Closer Hector Neris struck out the side in the ninth while converting his 19th consecutive save opportunity.

"They shut us down," Nationals manager Dusty Baker said. "I was putting a lot of players in there to give them some at-bats and keep them sharp. But their bullpen came in and do a good job against us."

The Phillies got an insurance run in the seventh on a Rhys Hoskins sacrifice fly.

Thompson allowed a leadoff single and walked Harper on four pitches to open the game. But he quickly found a double-play ball before later striking out Ryan Zimmerman to escape a 22-pitch first inning without surrendering a run.

In the second, though, former Phillie Howie Kendrick belted a solo home run to open the scoring and give Washington a 1-0 lead.

Harper, who played for the first time since Aug. 12 (left leg injuries), batted three times and was removed after his fifth-inning pop out in the top of the fifth. The slugger finished 0-for-2 with a walk.

"He looked pretty good," Baker said. "His timing is off a little bit. But he moved around and I didn't see any signs of limping or real fatigue. We got him out of there at about the right time. The more pitches he sees, the better and quicker his timing will get there."

Baker and Harper said his status for Wednesday is up in the air.

"I feel fine," Harper said. "Just try and get past tonight and see what I feel like tomorrow. If I feel good then I'll play. If I don't, take a day and see what I feel like the next day."

NOTES: Washington leads the season series 11-7. ... Philadelphia's bullpen entered Tuesday with a 2.74 ERA in its previous 28 games. That mark ranked fourth in the majors during that span. ... During the same stretch, Washington's bullpen ranked third at 2.28. ... The Phillies have won nine of their last 15 games. ... In the series finale Wednesday, Washington RHP Tanner Roark (13-10, 4.41 ERA) faces off against Phillies RHP Mark Leiter Jr. (3-6, 4.69).