Belliard's grand slam helped Balester become the first Nationals starter to win his debut as Washington beat the Florida Marlins 9-6 on Tuesday night.
"When I first went out there warming up I was real nervous," Balester said. "I was sitting out there just looking at everything. It was amazing, you're finally in the big leagues."
Balester gave up one hit and struck out three in five innings to become the first franchise starter to win his debut since Dan Smith on June 8, 1999, when the club was still in Montreal.
"Those last four innings seem like it took four hours," Balester said.
Belliard's second career grand slam in the sixth put the Nationals ahead 6-1, improving Washington's record to 2-9 this season against Florida. He also hit a grand slam Aug. 25, 2005.
But it was Balester's performance that had the Nationals giddy.
"He has a lot of heart," Washington's Dmitri Young said. "I was going to say something else, but that might not make it to print."
Hanley Ramirez tried to spark another late Marlins rally, hitting a three-run homer in the seventh to cut Washington's lead to 6-4. His 20th of the season was his third home run in three days after hitting tying homers in the ninth in consecutive Florida comebacks.
"It didn't matter, we lost the game," Ramirez said. "We've got to come back tomorrow and win the series."
Ramirez's career-high five-RBI game was lost in another shaky Marlins pitching performance.
Mark Hendrickson (7-7) allowed six runs and 10 hits in six innings for the Marlins. Florida's Opening Day starter is 0-5 in seven starts since beating San Francisco on May 25.
"I was trying to nitpick and all of a sudden, I give up a couple of hits here and there," Hendrickson said. "I was aggressive and I even stayed aggressive after the grand slam. Right now I'm getting hurt by mistakes and they're making us pay."
After Washington took a 9-4 lead in the eighth, Ramirez and Alfredo Amezaga hit RBI singles in the bottom half to make it 9-6.
Elijah Dukes homered for the second day in a row, a solo shot in the fourth that gave the Nationals a 1-0 lead.
Marlins second baseman Dan Uggla was out of the lineup a third straight game after he sprained his left ankle Saturday. He was scheduled to have an MRI on Tuesday. Uggla reiterated that he is hoping to return sometime during the team's four-game series at Colorado, which begins Thursday. ... The Marlins and Nationals will play a rare weekday afternoon game in Miami at 12:10 p.m. Wednesday in the final game of the series.