Roberson scored 20 and Singletary had 16 to help Texas Tech (12-8, 3-3 Big 12) stay unbeaten at home this season and avenge a 19-point loss to the Cowboys in its conference opener in Stillwater last month.
That victory was also the last for Oklahoma State (10-11, 1-6), which has lost six games in a row since.
Singletary got six of Tech's next 10 points and Roberson got his fourth 3 of the game as the Red Raiders pushed their lead back up to 53-41 with about seven minutes remaining.
Oklahoma State got within 59-55 at the 1:24 mark but Roberson and Alan Voskuil each got buckets to put it out of reach for the Cowboys.
The Cowboys, who tried desperately and unsuccessfully to score from outside, couldn't muster another rally. Oklahoma State tried 31 shots from behind the arc and made only six.
Tech hasn't lost a home game this season and have won 13 straight at home bridging into the 2006-07 season. The Red Raiders are 23-3 in Lubbock since the beginning of last season.
Tech's last loss at home was to Nebraska, 61-59, last February.
Tech led 34-24 at halftime, handing the Cowboys their lowest first-half output against a Big 12 opponent since they scored 23 against Nebraska in their finale last season.
At times the Cowboys were outgunned by a single Tech player. About 11 minutes into the first half, Roberson had more points (12) than Oklahoma State when the Cowboys trailed 12-11.
Neither team missed a free throw in the first half and the Red Raiders outrebounded the Cowboys 20-7 over that stretch.