Desmond homered, tripled and drove in three runs and the Nationals kept up their strong finish to a dismal season by beating the Atlanta Braves 6-3 Friday night.
The Nationals, who lead the majors with 103 losses, have a five-game winning streak, their second-longest string of the year.
"Every game now is like a playoff game. We're battling out there," Desmond said.
Desmond, the rookie shortstop who drove in four runs in his major league debut against Philadelphia on Sept. 10, is hitting .286 with three homers and 11 RBIs in 19 games.
"He's the kind of guy you can build with," Washington manager Jim Riggleman said.
The Braves have lost four straight. They were eliminated from the NL wild-card race on Thursday and have a more modest goal of avoiding third place in the NL East after falling into a second-place tie with Florida.
"We're not letting down," manager Bobby Cox said. "We're trying to finish second ahead of Florida."
Livan Hernandez (9-12) earned only his second win in his last nine decisions, giving up nine hits and three runs in 6 1/3 innings. He was 7-8 with the New York Mets before signing with Washington on Aug. 25.
"Livan is going to pitch somewhere next year, and odds are it will be with us," Riggleman said.
That sounds good to the 34-year-old Hernandez.
"I would like to play here next year," Hernandez said. "That's something I want to do."
Mike MacDougal pitched the ninth for his 20th save.
Derek Lowe (15-10) gave up five earned runs on eight hits and five walks in 4 2/3 innings. He finished the season with a 4.67 ERA, his highest since posting a 5.42 ERA in 2004, his last season in Boston.
Lowe said he's looking forward to trying to correct mechanical flaws in the offseason.
"I don't know where I went wrong," Lowe said. "I just got into so many bad habits as far as mechanics. I tried to correct it. It was never there.
"It's disappointing. It's frustrating, But it's over."
Lowe's ERA was under 4.00 four straight seasons with the Los Angeles Dodgers, including a 3.24 mark in 2008.
"I'll get ready to come back next year with different stuff, be more competitive," he said.
The Nationals' first five hits off Lowe were for extra bases, including a second-inning homer by Desmond. David Ross had a two-run double for Atlanta in the bottom half.
Washington took a 4-2 lead in the third. Justin Maxwell led off the inning with a triple. Desmond added a two-run triple in the right-field corner.
The Nationals added two runs off Lowe in the fifth. With one out, Ryan Zimmerman singled and had to scramble back to first when Nate McLouth made a running catch at the top of the center-field wall on a drive by Josh Willingham.
Lowe walked Desmond and gave up a single by Alberto Gonzalez that drove in Zimmerman. Desmond scored when left fielder Garret Anderson's throw skipped past Ross at the plate. Anderson was charged with an error.
Chipper Jones, who won the NL batting title last season by hitting .364, is 100 points below that mark with two games left. He was 0-for-5 to fall to .264. Jones drove in McLouth with a seventh-inning groundout.
Martin Prado had four hits for Atlanta, his third four-hit game of the season.
Washington won eight straight from Aug. 2-9. ... The Braves were without OF Ryan Church, who was with his wife, Tina, in Viera, Fla., for the birth of the couple's second child, Madison Noel, on Friday afternoon. ... Atlanta's Omar Infante had three hits as the fill-in starter in right field when Matt Diaz was scratched with a jammed right thumb. ... Lowe's five walks, including one intentional, matched his career high.