Updated

Markel Brown scored a season-high 23 points, Le'Bryan Nash added 20 and No. 20 Oklahoma State cruised to an 81-58 victory over Portland State on Sunday in its first game as a Top 25 team in five years.

Phil Forte chipped in 15 points and Marcus Smart had eight points and nine assists, the third most for a freshman in Cowboys' history.

Already up by 18, Oklahoma State (5-0) put the game away with a 13-2 run to start the second half, giving the Cowboys a 53-24 lead. Brown connected on a runner and a 3-pointer and then punctuated the spurt by driving for a two-handed reverse dunk. Portland State (1-3) was never closer than 20 after that.

Renado Parker and Michael Harthun led the Vikings with 12 points apiece. Top scorer Dre Winston Jr., a transfer from Washington State, missed all five of his shots and was held scoreless.

Winston had been averaging 14.7 points and led the team in scoring in each of the first three games this season. Portland State fell to 0-3 on its four-game road trip.

The Cowboys climbed into the Top 25 this week for the first time since 2007, following a perfect run through the Puerto Rico Tipoff and an upset of then-No. 6 North Carolina State in the tournament championship game. The game marked the first time Oklahoma State has been ranked under fifth-year coach Travis Ford.

Oklahoma State went with a seven-man rotation with Brian Williams and Jean-Paul Olukemi both out for the season and Michael Cobbins (toe) and Marek Soucek (knee) still recovering from injuries. That hardly slowed the Cowboys, who never trailed.

Brown and Philip Jurick came up with blocked shots on two of Portland State's first three possessions and raced to a 14-3 lead, with Smart setting up a right-handed dunk by Brown and a two-handed slam by Kamari Murphy.

The dunks kept coming as Oklahoma State's lead continued to grow, with Kirby Gardner lobbing to Brown for a two-hander coming out of a timeout. Smart then set up three straight baskets — dunks by Brown and Jurick and then a Brown 3-pointer — during a 7-0 stretch that pushed the Cowboys' lead to 31-12 with 6½ minutes left before halftime.

Portland State hadn't faced a ranked opponent since December 2009, when it beat rival Portland, which was No. 25 at the time.