MIAMI -- An ailing Bryce Harper required intravenous fluids before the game, vomited once between innings and repeatedly bent over in discomfort before stepping into the batter's box.

His swing was as robust as ever, though.

Back in the lineup after missing one game with the flu, Harper went 4-for-5 on Wednesday night to hike his average to .364 and lead the Washington Nationals past the Miami Marlins 6-1.

"I didn't feel very good at all," Harper said. "Getting in the box and swinging made my head spin a little bit."

Bryce Harper didn't let a bout with the flu keep him from going 4-for-5 on Wednesday night, including this RBI single in the ninth inning against the Marlins. AP Photo/J Pat Carter

He made the Marlins dizzy, too, and helped Ross Detwiler earn his first victory of the year. Harper singled in his first two at-bats, doubled and scored in the sixth inning and drove in Washington's final run by beating out an infield hit.

"I wanted to play," he said. "My team needed me out there. I thought I could help the team win. I didn't really care if I was sick or not."

Harper went 3-for-3 against Ricky Nolasco and improved to 9-for-20 (.450) against the right-hander. Harper hit two solo homers off Nolasco on Opening Day.

"Now it's to the point where I make good pitches and they're still falling," Nolasco said. "Every time I break his bat or make good pitches, they're still hits."

Detwiler (1-0) allowed one run in seven innings, which actually increased his ERA to 0.90. He left his first two starts with the Nationals ahead 5-1 and 4-1, but both times received no decision.

This time Washington's relievers came through. Tyler Clippard and Rafael Soriano pitched one perfect inning apiece to close out a seven-hitter.

"We have a great bullpen," Detwiler said. "Nobody wants to face the guys we have coming out of the bullpen, so it's really comforting to see those guys jog out."

Detwiler threw a career-high 107 pitches, almost all of them fastballs.

"He should be 3-0," manager Davey Johnson said. "He has been outstanding."

Kurt Suzuki hit his second home run, tripled and had a sacrifice fly. Adam LaRoche had two hits to improve his average to .195.

The Nationals, who took two of three games from the Marlins, have won only four of 19 series in Miami since the beginning of 2007. This year Washington is 5-1 against the Marlins and has outscored them 29-13.

The Marlins finished a nine-game homestand with the worst record in the majors at 3-12. They're also last in the majors in runs (32) and homers (three).

Giancarlo Stanton sat out for the sixth consecutive game because of a bruised left shoulder, but he's expected to rejoin the lineup Thursday in Cincinnati.

Another bright spot for the Marlins: Announced attendance was 22,302. Despite the team's dismal start, crowds have been larger than many expected in the wake of offseason moves that angered fans.

The Nationals took the lead in the second, when they scored twice. LaRoche and Ian Desmond singled, Roger Bernadina had an RBI groundout and Suzuki followed with a sacrifice fly.

Suzuki homered on a 3-2 pitch leading off the fifth. Harper doubled and scored on LaRoche's single in the sixth to make it 4-1.

"I thought Harper was going to die every time he went up there, and he got another hit," Johnson said. "He didn't have a smile on his face the whole game. But I'll give him off Thursday."

That's because the Nationals have the day off. They open a series at the Mets on Friday.

The Marlins scored a disputed run in the fifth, when Chris Valaika doubled and came home on a two-out single by Donovan Solano. It appeared Suzuki tagged the sliding Valaika just before he touched the plate, and umpire Greg Gibson began to signal out before changing his call to safe.

Johnson briefly argued.

"I said, `You had it right, and then you changed it," Johnson said. "We survived it."

Game notes

Nationals 3B Ryan Zimmerman left in the eighth inning with cramps in his left hamstring but said he expects to play Friday. OF Denard Span missed his second game in a row with the flu but was feeling better. 2B Danny Espinosa remained out with a bruised right hand but is expected to play Friday. ... Marlins SS Adeiny Hechavarria was scratched from the lineup 90 minutes before the game with a sore right elbow and will be further evaluated. Valaika, who replaced Hechavarria, has now started at all four infield positions this month. ... Miami RHP Henderson Alvarez (shoulder) threw 35 pitches in a bullpen session and may pitch a simulated game next week. ... Jayson Werth went hitless and has a career average of .118 (4 for 34) against Nolasco. ... The retractable roof was open for the fifth time in nine games.