Nicholas and Bailey had key jumpers down the stretch for the Pilots (3-3) after the Pioneers trailed by just two, 71-69, with 2:17 remaining. Nicholas' two free throws clinched the game, making it 77-70 with 17 seconds to play.
In a game with eight lead changes and five ties, the Pilots' seven-point cushion in the second half was the largest for either team.
Both teams made half their attempts from the floor, with Portland shooting 29 of 57, Lewis & Clark 27 of 54. While the Pilots enjoyed a 34-16 scoring advantage in the paint, the Pioneers made 14 of 26 shots from 3-point range.
Derrick Rodgers added 11 points for Portland.