The Panthers and Eagles traded scoreless innings until the sixth, when the Eagles scored all four of their runs.
With runners on the corners, Brandon Gali singled to score Piatt, making it 3-0.
Keith Oren then lined an RBI single to score Ondrejka and give the Eagles a 4-0 advantage.
South Florida got two runs in the eighth, but Gamble came on in the ninth to get three straight strikeouts. His nine saves tie him for first among FCSAA Division 1 Region 8 (Florida) pitchers.
In six innings, Barrett gave up five hits while walking two and striking out nine. His 0.44 ERA leads all FCSAA Division 1 Region 8 pitchers.
After the game, Head Coach Al Corbeil talked about the key roles those two hurlers have played.
"Barrett has solidified himself as one of the best starters in the country right now. He's throwing a lot of pitches for strikes, and he did another fantastic job tonight. And then Gamble has been slamming the door shut pretty consistently, so it's nice to have those two guys on our pitching staff."
Piatt had a three-for-three night. He scored a run and had an RBI.
Osborne and Ondrejka each singled, scored a run, and drove in a run.
Gali had a single and an RBI.
Parker singled, stole a base, and scored a run.
The Eagles (23-8, 7-1, No. 5 in the FCSAA Coaches' Poll) play South Florida again Wednesday in Avon Park at 6 p.m.