Ricky Nolasco came into the game with a 6.70 ERA since the All-Star break, while Stephen Strasburg had won his past four starts.
The pairing looked like a mismatch, and it was. Nolasco pitched a five-hitter for his third career shutout, and the Miami Marlins drubbed Strasburg and the slumping Washington Nationals 9-0 Tuesday night.
Nolasco (10-12) pitched his eighth complete game and second in the past three starts.
"It's nice," he said. "Any time you're rolling like that you want to finish it off."
Strasburg (15-6) gave up a career-high seven runs in five innings, and the first-place Nationals' losing streak reached five games.
Strasburg came into the game with a streak of 27 consecutive scoreless innings against Miami in five starts since last September. But he gave up a homer to his second batter, Justin Ruggiano, and trailed 5-0 by the third inning.
"He's the toughest I've faced in a game as far as overall stuff," Ruggiano said. "Hopefully he's tipping his cap to us, because I think we all had a good approach to him."
The Nationals began the night with baseball's best record, but they're saddled with a losing streak that matches their season high.
"We've played really good 90 percent of the year," manager Davey Johnson said. "We're in a rough spot here. That makes the metal hotter. The tougher it gets, the stronger you get, so we'll be fine."
Strasburg said the Marlins adjusted to his inside fastball and didn't try to hit the ball the other way.
"They had a little different approach this time, and I didn't make the adjustment," he said. "I just kept trying to do the same thing."
Strasburg is expected to make perhaps four more starts before the Nationals shut him down for the year to protect his surgically repaired elbow. The drubbing doesn't change that plan, Johnson said.
The young right-hander allowed five earned runs and gave up nine hits to match a career high. He struck out only three but leads the NL with 186 strikeouts.
"The guy's one of the best in the game," Nolasco said. "Everybody's going to have an off night. We're just lucky we caught him on it."
Nolasco struck out five, walked none and lowered his ERA to 4.78. He retired 14 in a row and held the Nationals hitless until Kurt Suzuki singled with two outs in the fifth.
"When Ricky throws strikes, he can be effective," Miami manager Ozzie Guillen said. "All his pitches were working today."
Ruggiano had a career-high four hits in four at-bats and drove in two runs, while Giancarlo Stanton added three hits and three RBIs. Seven of the Marlins' runs scored with two outs, and they totaled 13 hits.
The Marlins scored twice off Strasburg in the first inning. Ruggiano hit his 13th home run. Carlos Lee doubled with two outs, then came home on a broken-bat single by Stanton.
Miami added three runs in the third. Bryan Petersen led off with a single, stole second, took third on a groundout and came home when second baseman Danny Espinosa mishandled a grounder for an error. Greg Dobbs' two-out single brought home two unearned runs to make it 5-0.
Ruggiano had a two-out RBI single against Strasburg in the fourth. Donovan Solano extended his hitting streak to 11 games with a two-out RBI single in the fifth off Strasburg to make it 7-0.
"Any team wants to come out and make a name for themselves off Stephen Strasburg," Nationals shortstop Ian Desmond said. "The guy is one of the best pitchers in the game, and they're not just going to lay down for him."
NOTES: Nolasco had been 0-2 with a 6.35 ERA in his two previous starts this year against Washington. ... Jayson Werth went hitless and is 4 for 25 (.160) against Nolasco. ... The Marlins' bullpen hasn't allowed an earned run against Washington in the past 31 1-3 innings.