"I was going to take him out, but he said, 'It's my game and I'm going to get out of this,' " Nava said. "It worked."
With runners at second and third and no outs, Fleet struck out the next two batters and forced a ground out to end the inning in a 7-6 victory.
"Lipso trusted me," Fleet said. "It was important for me and for the team because we were up, and I was just trying to get outs. Pitching with a lead is so much easier. It's less stressful."
Fleet (3-2) pitched with a lead after the GreenJackets scored four runs in the first inning. Seventeen days after West Virginia starting pitcher Colton Cain dominated Augusta's batters, the Pittsburgh Pirates' eighth round draft pick from 2009 couldn't repeat his April 17 performance when he allowed just one hit over six scoreless innings at Lake Olmstead Stadium.
Instead, the 20-year-old lefty fell victim to control problems and a pair of costly errors behind him. He surrendered four unearned runs in the first inning on two hits, two walks and two fielding miscues.
The GreenJackets (9-18) were outscored 23-6 in their previous two games but got a scheduled day off Wednesday and returned to Augusta with their bats poised for a big night in front of an announced crowd of 3,835.
All nine GreenJackets starters reached base safely at least once. Left fielder Rafael Rodriguez extended his hitting streak to 13 games and drove in two runs with a 2 for 5 night.
Catcher Jeff Arnold went 3 for 4 with two RBI, and newly activated shortstop Bobby Haney got his first hit as a GreenJacket with an RBI single in a two-run the seventh.
"We got some timely hitting," Nava said. "Some days it's hitting, some days it's pitching, but those pieces of the puzzle are starting to come together."
Augusta needed all seven runs after shaky bullpen work allowed West Virginia back into the game late.
Fleet allowed one earned run and no walks over five innings and gave way to reliever Gaspar Santiago, who struck out all three batters he faced for a perfect sixth.
Jacob Dunnington threw a scoreless seventh, but newly acquired lefty Tom Vessella struggled in an eighth inning that saw the Power bat around and score three times to pull within one.
Drew Bowlin stopped the bleeding in the eighth, and Stephen Harrold slammed the door with a perfect ninth for his second save.
West Virginia's rain out in their final game before coming to town shifted the Power pitching rotation enough to bump former Greenbrier High School starting pitcher Brandon Cumpton off the list of probables for the four-game series in Augusta. Cumpton's next start is scheduled for Monday when West Virginia begins a four-game series in Charleston.