Carrasco hasn't given up a run in his last 17 2/3 innings. The only time he was in trouble on Monday was in the first inning. The Marlins had the bases loaded and no outs, but he got Juan Encarnacion to fly out to Brad Wilkerson in left field and induced Mike Lowell to hit into a double play to end the inning.
"Hector has been a nice, pleasant surprise with another great effort on his part tonight," said Robinson. "He has pitched four good starts. I don't know how he does it at this stage of the season. He seems to thrive on it."
The 35-year-old Carrasco, who lowered his ERA to 1.73, is surprised that he has been able to make the successful transition from reliever to starter.
"This is the first time in my career that I've been pitching the way I've been pitching," said Carrasco. "But I'm going to keep doing this. I have a lot of confidence in myself, and I'm not afraid."
Marlins left-hander Jason Vargas was just as effective, pitching seven innings and giving up one run on five hits.
That one run was scored in the second inning, when Cristian Guzman drove in Nick Johnson with a single to left field.
The Nationals scored three insurance runs off reliever Antonio Alfonseca in the top of the eighth inning. Ryan Zimmerman singled up the middle to drive in Jamey Carroll.
"He left a slider over the plate," said the 20-year-old Zimmerman. "I was trying to stay back. I felt I was a little jumpy in the first few at-bats."
Zimmerman, who is expected to be the everyday third baseman next year, went 2-for-4, raising his batting average to .421 and his RBI total to six. He is not surprised by his success at the plate.
"I have confidence in myself," he said. "I believe I can perform up here."
Guzman put the icing on the cake by driving in two more runs with a double down the left-field line off Alfonseca.
"He has been our offensive weapon the last month," said Robinson. "Another big game from him. At least he is a threat up there at the plate now, which makes a big difference down in the bottom of the lineup."
Overall, Guzman went 3-for-4 with three RBIs and raised his average to .215. It's his highest batting average since May 15, when he hit .226. Guzman is having his best month of the season, hitting .328 (21-for-64).
"I feel good," said Guzman. "Like I [said] all year, when you do something in the game, you have to be happy. For me, I want the season to start right now, but it's almost over. I'm going to keep going the last five games and improve the numbers."
The victory snapped the Nationals' three-game losing streak and improved their record to 79-78.
"They see the finish line, but they don't want this season to slip away and finish under .500," said Robinson. "They have pride, and they want to finish as well as they can. There's a lot of nicks and ailments here, but they are still going out there and giving me the effort."