HOUSTON - Chris Douglas-Roberts scored 30 points and Joey Dorsey grabbed 22 rebounds, matching a career high, as top-ranked Memphis equaled the best start in school history with an 89-77 win over Houston on Wednesday night.

Memphis' Chris Douglas-Roberts (14) drives past Houston's DaShaun Williams in the second half of basketball play Wednesday, Jan. 30, 2008 in Houston. (AP Photo/Pat Sullivan)

Robert Dozier 17 of his 21 points in the second half and the Tigers (20-0, 6-0 Conference USA) overcame a season-high 22 turnovers to extend their regular-season winning streak to 39 games. Memphis matched its best start since 1985-86 and won its 15th consecutive road game.

Dion Dowell scored 23 points and Robert McKiver scored 20 for the Cougars (15-4, 4-1), who dropped to 2-10 all-time against the No. 1 team. Houston coach Tom Penders was also denied his 600th career victory.

Memphis outrebounded the smaller Cougars 49-29 and scored 44 points in the paint.

The Tigers led 46-35 at the break and started the second half with a 10-4 spurt. Dowell hit three free throws and a 3-pointer over the next two minutes as Houston pulled within 13.

Memphis pushed the lead to 17, but the Cougars' scrambling, full-court pressure forced five turnovers in four minutes during a 12-3 burst that closed the gap to 66-58. Memphis' lead hovered between eight and 10 until Douglas-Roberts finished a fast break with a dunk for a 74-62 lead. Dozier added two baskets down low as the Tigers finally pulled away.

Dorsey swiped a rebound with one hand and threw down a dunk in the closing minutes, sealing the Tigers' 29th consecutive victory in Conference USA.

Memphis, the league's best defensive team, held high-scoring Houston to 35 percent shooting from the field (24-of-68). The Cougars average 10 3-pointers per game, but went 6-for-24 from long range against the bigger, faster Tigers.

The Tigers struggled early with Houston's trapping defense and trailed 11-4 after giving away four turnovers in the first four minutes.

Memphis quickened the pace and charged ahead with an 13-0 run, capped by back-to-back 3-pointers by Willie Kemp. The Cougars were suddenly sloppy and went three minutes without scoring. Kelvin Lewis sank two free throws to cut Houston's deficit to 24-20, but the Tigers stayed in control.

Douglas-Roberts scored eight quick points and Kemp drove through the Cougars' defense for a layup to stretch the lead to 36-25. McKiver's long jumper with 7:46 left before halftime was Houston's only field goal for six minutes.

After a hot start, the Cougars ended up 12-of-37 (32 percent) from the field in the first half with only three 3-pointers.

The Cougars were facing the No. 1 team for the first time since a 77-65 loss to Cincinnati on Feb. 17, 2000.