Robert Arnold scored 16 points and La'Shard Anderson added 13 to lead Boise State past Idaho 69-63 on Saturday night.
Boise State (14-11, 7-6 Western Athletic Conference) completed a season sweep of the Vandals for the first time since the 2007-08 season.
Idaho (14-11, 7-6), which upset No. 21 Utah State in Moscow on Wednesday, became the first road team to lose in this series in five games.
The Vandals led 62-61 with 1:44 to play but went cold, failing to make another shot from the floor. Boise State regained the lead and held on behind an 8-for-8 performance from the free-throw line in the final 90 seconds.
Arnold's 3-pointer with 10 seconds remaining in the first half gave the Broncos a 36-33 lead at the break.
Jeff Ledbetter led Idaho with 19 points, including 6 of 8 from 3-point range, while Landon Tatum added 13.