K.J. Windham matched a career high with 20 points and Nick Martinelli added 16 points and nine rebounds to help Northwestern defeat Iowa 68-57 on Friday in Evanston, Ill.Northwestern won its third straight game, shooting 42.3 percent while limiting Iowa to a 36.2 percent effort from the floor. Drew Thelwell helped keep the Hawkeyes afloat with 14 points on 5-for-7 shooting, including 4-for-4 accuracy from behind the arc.Northwestern (16-13, 7-11 Big Ten) bolstered its chances of qualifying for next month’s conference tournament in Indianapolis while hurting those of Iowa (15-14, 6-12). The top 15 of the league’s 18 teams make the cut.Minnesota and USC each have six conference wins with a game in hand on the Hawkeyes, while Penn State (five Big Ten victories) and Washington (four) also remain in the hunt.Iowa slumped to 34.5 percent shooting in the first half but showed more effectiveness to start the second. The Hawkeyes pulled within 37-36 on a Thelwell 3-pointer with 16:17 remaining but were unable to get over the hump in a game in which they never led.Martinelli, who entered the night as the Big Ten’s leading scorer at 20.1 points per game, managed just four first-half points on 1-for-8 shooting. He grabbed six early rebounds, however, including three on the offensive glass.Windham, a freshman guard, helped pick up the slack. He also scored 20 points in a Feb. 11 loss at Oregon. Justin Mullins added 10 points for Northwestern.