PORTLAND, Ore. — Marvin Bagley III said the Blue Devils knew they had to wake up for the second half against Portland State.
And eventually, they did. Trevon Duval had 22 points as No. 1 Duke pulled away for a 99-81 victory over the surprisingly tenacious Vikings on Thursday to open the Phil Knight Invitational.
Bagley added 18 points, and Grayson Allen had 14 points and nine assists. The Blue Devils (6-0) will face the winner of the Thursday game between Butler and Texas.
Duke trailed by as many as eight points but took control midway through the second half when Wendell Carter Jr.'s dunk put the Blue Devils in front 67-62. They would go on to lead by as many as 21 points.
"The first half we obviously weren't playing like we were normally do. We weren't doing the things that we do well. We weren't going to our strengths. We kind of came out sluggish," Bagley said. "But going into the second half it was just 'You have to wake up.' They (the coaches) mentioned to us that these are the type of games that are going to be like that if you don't come out ready to play.
It was coach Mike Krzyzewski's 200th victory as coach of a No. 1-ranked team. He's 200-29 when the Blue Devils sit atop the poll.
Deontae North led the Vikings (4-1) with 24 points, including 20 in the first half, but fouled out with 8:39 left in the game.
It was the first time in program history that the Vikings had faced a top-ranked team. Portland State's last win over a ranked opponent was an 86-82 victory over then-No. 25 Portland in December 2009.
"I thought they just knocked us back the whole first half," Krzyzewski said. "We were in a reactionary mode the first 20 minutes."
The tournament involves 16 teams playing in two brackets on Thursday, Friday and Sunday, with a break on Saturday. The field also includes No. 4 Michigan State, No. 7 Florida and defending national champion North Carolina.
Dubbed the PK80, the tournament celebrates Nike co-founder Phil Knight's 80th birthday.
Duke and Portland State were in the Motion Bracket, playing Thursday at the Memorial Coliseum. Teams in the Victory Bracket played at the adjacent Moda Center.
Knight was sitting courtside for the game.
The five-time NCAA champion Blue Devils were coming off a 92-63 victory over Furman on Monday night, led by Bagley with 24 points.
Portland State was coming off an 83-79 victory over Utah State at the Memorial Coliseum on Monday. The Vikings are playing the first season under coach Barret Peery.
"I'm proud of our team," Peery said. "But I was proud of our team before the ball went up."
Portland State was no pushover from the start, taking a 12-11 lead on North's 3-pointer with 16:54 to go in the opening half. North hit another 3 that put the Vikings up 19-15 and Michael Mayhew's jumper extended the lead.
North made another 3 to make it 33-26 with 8:33 left in the half. The Vikings stayed out in front until Gary Trent Jr. made a pair of free throws for Duke to tie it at 42 with 2:09 left in the half.
Mayhew hit a long 3-pointer and Portland State led 49-45 at the half. Mayhew was among five Vikings who fouled out in the second half.
Carter's layup put Duke out in front 54-53, but North answered with a jumper and Bryce Canda added a 3-pointer.
Carter had another layup to give the Blue Devils a 61-60 lead and Bagley's tip-in pushed the lead to 63-60, energizing the mostly blue-clad crowd at the Coliseum. Duke never trailed again.
"This was a big stage for us," said Canda, who finished with 14 points. "But we can't hang our heads."
HAMPTON 76, N. ARIZONA 66: Jermaine Marrow had 19 points, six rebounds, eight assists and four steals in the Las Vegas Invitational to help Hampton keep Northern Arizona winless. Hampton led by as many as 19 points in the first half and had a 12-point lead at halftime. Marrow was just 2 of 8 from the field in the opening 20 minutes and finished 4 of 14. But he made 10 of his 12 free throws as the teams combined for 55 attempts in the game. The rest of Marrow's teammates shot a combined 56 percent (23 of 41) from the field. Charles Wilson-Fisher had 13 points and 13 rebounds, and Akim Mitchell added 10 points for Hampton (2-4). Torry Johnson led Northern Arizona (0-5) with 24 points on 7-of-19 shooting. He was 7 of 12 from the free-throw line as the Lumberjacks hit only 16 of 28.