BOULDER, Colo. (AP) - A torrid second half by Askia Booker was just enough to offset a career night by DaVonte Lacy.
Booker scored 21 of his 26 points in the closing period, including six of eight free throws in the final minute, and Colorado overcame a career-best 34-point performance by Lacy to beat Washington State 68-63 on Wednesday night.
"A win's a win, especially in conference play but it wasn't pretty at the end," said Colorado coach Tad Boyle. "In the second half, we blew it open - 19 (points) was our biggest lead - but we didn't finish like we want to or need to."
Xavier Johnson added 20 points and nine rebounds for Colorado (17-6, 6-4 Pac-12), which swept the season series with the Cougars. The Buffaloes won at Washington State 71-70 in overtime last month.
Ike Iroegbu added 10 points for the Cougars, who remain winless in five conference games on the road.
Lacy converted 10 of 19 shots from the field, including a career-high eight of 13 from 3-point range for Washington State (9-13, 2-8). It was his second game back from a rib injury that had sidelined him for a month. He missed the first meeting between the teams.
"My teammates did a good job of knowing that I was shooting the ball pretty well, set screens and got me open and the ball was delivered on time," Lacy said. "I was just able to hit shots."
So was Booker, though.
"Askia attacked the basket under control, got to the rim," Boyle said. "He was 9 for 12 (from the field) and when he's that efficient, our offense is pretty good."
Up by three at the half after a sluggish opening by both teams, Colorado got its offense going behind Booker.
"Coach just told me to be aggressive," Booker said. "I had to pick and choose my spots. I got right downhill, got to the basket and got some easy buckets in transition."
Booker scored 12 of the Buffaloes' first 13 points in a four-minute stretch opening the period and Colorado surged to 34-23 lead with 16:01 left to play. He punctuated the flurry with four straight field goals for Colorado, including a breakaway dunk off of a steal.
Lacy connected on his fifth 3-pointer to stall Colorado's momentum but Booker hit a jumper before Johnson countered a layup Iroegbu by converting a three-point play.
The Cougars, who trailed by 15 after a layup by Johnson, fought back to within 60-53 on a dunk Junior Longrus with 1:15 left to play.
Lacy then hit a pair of 3-pointers in the waning seconds, pulling the Cougars to 66-63 with six seconds remaining. Booker was fouled an instant after the inbounds but he made both free throws with two seconds left to secure Colorado's victory.
"Thank God we made those free throws at the end to hold them off," Booker said. "But at the same time, you can't let an individual come in here, especially on the road, and let him take over and let him keep his team in the game."
Added Boyle: "We'll take this and move on. We'll learn from this. We'll get better. Obviously, there's still a lot of room for improvement."
Colorado was held to a season low at home in points in the first half but got a 3-pointer and a layup from Johnson around a layup by Jordan Railey late in the period to take a 23-20 lead.
Benefiting from a 9-0 run early on, the Buffaloes led 15-7. But Washington State got right back in it with three 3-pointers in a five-minute stretch, including two by Lacy to help even the score at 18-all with 3:57 left in the first half.