Updated

When 6-foot-7, 240-pound Alan Williams committed his second foul less than 3 minutes in and was subbed for, the UC Santa Barbara Gauchos lost a big force in the middle and were in trouble.

No. 17 San Diego State went on a 14-0 run to take control early and beat future conference rival UC Santa Barbara 84-70 on Thursday night, the Aztecs' seventh straight win.

Chase Tapley scored 23 points, going 6 of 8 from behind the 3-point line, to lead five Aztecs in double figures.

"We had to go with three guards," UCSB coach Bob Williams said. "It neutralizes any chance we have of rebounding. Al will carry his weight but you have to keep him out of foul trouble. If we keep him out of foul trouble, the rebounding margin is going to be a little closer, the opportunities are going to be closer."

SDSU coach Steve Fisher said Alan Williams "is a load inside," but when he was on the bench, it hurt the Gauchos.

"There's a history of that when he leaves the game early," Bob Williams said. "It's not been a good thing for us."

Jamaal Franklin had 14 points, JJ O'Brien 12, Xavier Thames 11 and James Rahon 10 for the Aztecs (7-1), who join the Big West next season. It was their eighth straight victory over the Gauchos (3-5).

San Diego State hasn't lost since a 13-point defeat to No. 4 Syracuse in the season opener on the USS Midway.

The Aztecs made 11 of 17 3-pointers, a season-high 64.7 percent.

UCSB's Kyle Boswell made 7 of 10 3-pointers for a career-high 23 points. Alan Williams had 18 and Taran Brown 16 before they each fouled out late in the game.

The Gauchos' only lead was 5-4 after Brown made a 3-pointer 2 ½ minutes in.

San Diego State then took control with the 14-0 run. O'Brien scored six points and Tapley and Thames each hit a 3-pointer.

San Diego State led 46-29 at halftime. Tapley, Thames and Rahon all made two 3-pointers in the first half.

Early in the second half, the Aztecs made 3-pointers on consecutive possessions, the first by Thames and then two by Tapley. Tapley was fouled taking another 3-pointer and made all three free throws for a 64-37 lead with 15:10 to play.

"They are a team that you have to keep them from penetrating," Boswell said. "At the same time, they can shoot the ball extremely well. They have a bunch of weapons you have to respect. If you're going to give up one thing they are going to exploit you in another way."

The Aztecs have won 27 straight games against teams from California.