MIAMI -- Marlins manager Don Mattingly earlier said his team's playoff chances were on life support.

However, after Miami's third consecutive win -- a 1-0 victory over the Washington Nationals on Tuesday night -- perhaps it is time for an update.

The Marlins, as it turns out, are still breathing. The heartbeat may be feint, but if you listen closely enough, it's there, thanks in large part to the team's two superstars.

Jose Fernandez pitched eight scoreless innings, and Giancarlo Stanton hit a sixth-inning home run to give Miami the victory.

"Fernandez was outstanding," Nationals manager Dusty Baker said. "He didn't throw many sliders. He threw mostly fastballs and changeups.

"We had a predominantly lefty-hitting lineup, and he pitched accordingly."

Fernandez improved to an incredible 29-2 with a 1.49 ERA in his career at Marlins Park. In 10 career starts against Washington, Fernandez is 7-0 with a 0.99 ERA.

Overall this season, he is 16-8 with a 2.86 ERA.

"I thought that was best game Jose has thrown all year," Mattingly said. "He used his changeup early in the game. That was a weapon for him all night to keep them off balance. He was calm -- he wasn't overthrowing."

Washington (88-63), still ahead of the second-place New York Mets by 7 1/2 games in the NL East, has lost four games in a row.

Miami (76-75) trailed St. Louis and San Francisco by 3 1/2 games in the race for the second NL wild card pending the results of the Cardinals' and Giants' late games Tuesday.

The Marlins will go for a sweep of the Nationals on Wednesday. And they are clearly not intimidated by Washington.

After all, the Marlins are 18-17 against teams -- like Washington -- that were in first place at the time they played. The Marlins are 17-20 against teams that were in last place when they played, and that failing could cost them the playoffs.

Fernandez struck out 12 and allowed just three hits and no walks. It was his ninth double-figure strikeout game of the season, and he retired 21 consecutive batters before running into trouble.

In the eighth, Washington's Wilson Ramos hit a soft one-out single to center, and he was replaced by pinch runner Michael Taylor. With Miami's Miguel Rojas holding Taylor on at first, Brian Goodwin hit a chopper for a single to right. Had Rojas been playing at normal depth, it might have been a double play.

Instead, Fernandez faced his first real threat of the game -- runners on the corners with one out -- but he responded by striking out Danny Espinosa swinging and getting pinch hitter Daniel Murphy to bounce out to second.

Fernandez said the key was to use some finesse.

"That's the process of learning how to pitch," Fernandez said. "I tried to make a pitch, not overthrow. I didn't try to make it unhittable. I tried to make a pitch where they can't do so much damage. I tried to keep the ball down and get a ground ball."

Fernandez, who threw 111 pitches, has thrown 182 1/3 innings this season. The Marlins targeted him for 180 innings since it is his first full season after elbow surgery. That means it is possible this was Fernandez's final start of the season.

David Phelps pitched the ninth to earn his fourth save of the season.

In the sixth, Stanton swung at a 94 mph fastball by Tanner Roark (15-9) and hit it out to right field for his team-high 27th homer of the season.

Roark allowed just three hits and three walks in seven innings. The only run he allowed was to Stanton, who has 28 career homers against the Nationals. Among active players, only Ryan Howard (44) and Hanley Ramirez (31) have hit more homers against Washington than Stanton.

Baker said it was a shame to stick this loss on Roark, who lowered his ERA to 2.70.

"You boil it down to one pitch to a powerful hitter," Baker said. "(Roark's) been great all year -- a model of consistency."

NOTES: Nationals 2B Daniel Murphy (sore left leg) sat out his third straight start, although he appeared as a pinch hitter. ... Nationals RHP Joe Ross, who came off the disabled list and pitched Sunday, will start Saturday. ... Nationals backup C Jose Lobaton has a minor ankle injury. Washington has C Pedro Severino as a backup if needed. ... Marlins RHP Bryan Morris was designated for assignment. He had been on the 60-day disabled list due to a back injury. ... Marlins RHP Tom Koehler (9-10) will start Wednesday with a chance to win at least 10 games for the third straight season. He is 30-35 during that span. His task on Wednesday will be difficult: Washington starts RHP Max Scherzer (17-7, 2.78 ERA). Scherzer entered Tuesday tied for first in the NL in wins and sixth in ERA. He leads the majors with 259 strikeouts.