Fields finished with 17 points and Armon Johnson had 12 for the Wolf Pack (5-4).
Mark Dunn had 15 points, Kevin Winford scored 13 and Glen Dean had 13 points and 10 assists for the Eagles (4-6), who overcame an eight-point deficit with 6:21 left to tie it 70-70 with 1:22 left on a 25-foot 3-pointer by Benny Valentine.
Neither team could score on its ensuing possessions.
The Wolf Pack called time out with 12 seconds left, and Johnson found Fields on the right baseline for an open 3-pointer for the winner.
Dean's 3-point attempt at the buzzer fell short.