The Spartans\' Jen Nicholls scored a game-high 31 points, and the Dubuque defense held the Pioneers 20 points below their average.
The Pioneers, who had been averaging better than 82 points per game in their first three wins, were limited to 40 percent from the field, including 4-20 three-point shots, and 60.9 percent from the free throw line.
Despite the shooting woes, the young Pioneers kept the pressure on the Spartans. Trailing 34-28 at the half, the Pioneers outscored UD 15-3 to begin the second period, taking a 43-37 lead. Dubuque eventually tied the game at 43 and again at 47 before going on an 8-2 run. Nicholls scored a basket and free throw, then made a three-point shot. Jennifer Bell\'s jumper at 9:09 made the score 55-49, and the Pioneers never caught up again.
Senior Liz Tesch led the Pioneers with 21 points and eight rebounds, while sophomore Lisa Wubben had 11 points. Freshman Charity Stotmeister came off the bench to score seven points and make four steals.
Nicholls made 8-15 from the field and all 12 shots from the free throw line. No other Dubuque player was in double figures.
Both teams are now 3-1 and conclude the MRC Challenge Saturday. UW-Platteville faces Loras at 1 p.m., while Dubuque plays host Clarke at 6 p.m.