SEATTLE — Bryce Harper's progress from his hand injury helped ease the sting of the Washington Nationals' 5-3 loss to the Seattle Mariners on Sunday.
Harper hit two long home runs, giving him seven in his last 23 games for the NL East leaders.
Harper had his fifth career multihomer game. He is hitting .306 with seven home runs and 14 RBIs since Aug. 7, and went 6 for 12 with three homers in the series.
The All-Star outfielder missed 57 games with an injured left thumb before returning June 30.
"It's significant that he feels good," Nationals manager Matt Williams said. "You miss that kind of time, it takes time to get your rhythm and timing back."
"His hand is getting stronger. It allows him to stay back and calm and keep his body down a little bit. We've seen that over the last couple weeks. It's getting there," he said.
Harper is hitting .268 with 10 home runs and 28 RBIs this year.
"I feel pretty good out there, trying to put together some good ABs and get my work in every day," he said.
Nate Schierholtz also homered for the Nationals. They hit 10 home runs in the series, one short of the Safeco Field record for a three-game set established by Cleveland in 2009.
Washington has lost four of six. Seattle had lost three in a row, and had been 0-11 against the Nationals since the franchise moved from Montreal to Washington for the 2005 season.
Ackley also singled home a run, and tied his career high with four RBIs in a game. He is hitting .319 with 19 extra-base hits since the All-Star break.
Hisashi Iwakuma (13-6) picked up the win for the Mariners, who averted a three-game sweep.
Harper hit a 418-foot, solo homer in the second, the first run Iwakuma had allowed against National League teams in 23 innings.
Harper hit a 416-foot shot to straightaway center in the fourth.
Roark, who lasted 6 1-3 innings and gave up four runs and 11 hits, said it came down to "just one bad pitch" to Ackley.
"I made a mistake and threw a fastball in," Roark said. "It was first and third and one out, threw a fastball, just cut it a little bit and it was in his sweet spot."
Relievers Charlie Furbush, Danny Farquhar and Yoervis Medina combined to work two hitless innings. Fernando Rodney gave up a leadoff single to Harper in the ninth before getting his 39th save in 42 chances.
The Mariners added a run in the eighth on Endy Chavez's RBI double.
"The Nationals are a great team," Mariners manager Lloyd McClendon said. "They're a veteran ballclub that grinds out at-bats, making it tough on pitching. There are no easy outs in the lineup."
McClendon missed the previous two games to attend his daughter's wedding in Indiana. Bench coach Trent Jewett had been serving as interim skipper.
Nationals: Washington, which has the best record in the NL, open a three-game series Monday night at Dodger Stadium, where Los Angeles has the second-best record in the league. Nationals LHP Gio Gonzalez (6-9) faces RH Roberto Hernandez (8-9).