UIS got on the board before the crowd had time to settle into their seats as Anthony Longo scored on a feed from Michael Waldo just 58 seconds into the match.
It stayed 1-0 for most of the night but the Fighting Saints got back into the contest at the 74:02 mark when Tony Sallese (Plainfield Central H.S./Plainfield, IL)scored on a pass from Matt Gorecki (Oak Lawn H.S./Oak Lawn, IL) and that is how regulation time ended.
USF sealed the victory when Matt Nieciunski (Stagg H.s./Palos Hills, IL) posted an unassisted goal at the 101:20 mark.
It was an even match on the stat sheet as St. Francis had 14 shots to UIS' 13 and the Fighting Saints had eight corners while the Prairie Stars had six.
USF is off until a week from Saturday when the Saints play host to their own four-team tournament on Sept. 12 and 13. USF will play McKendree on Sept. 12 and Missouri Valley on the 13th.