A 15-point first half by Ivan Elliott was just what UCSB needed to establish control early against a dangerous Cal State Fullerton team that would not quit. The Gauchos needed some stamina of their own, though, as they hung on for an 83-80 victory Thursday at the Thunderdome.

Despite a 22-9 early lead and sizzling shooting (five of seven three-pointers and 60 percent from the floor), UCSB (17-5 overall, 6-3 in the Big West Conference) could only open up a 44-37 halftime lead. That’s nowhere near safe against Fullerton’s multipronged offensive threat.

The Titans (14-7, 7-3) surged repeatedly behind Marcus Crenshaw’s 21 second-half points, keeping the Gauchos’ lead to within three to five points throughout the half. Crenshaw, a 5-foot-10 lefty with a mild Mohawk, had lit up the Gauchos for 23 points a year ago, and looked poised to do it again, draining multiple threes and driving through the defense repeatedly for crazy baskets.

Fullerton’s leading scorer, Josh Akognon, smoldered (eight points), but Crenshaw (23), Frank Robinson (16) and Scott Cutley (14) blazed to even the score at 69 with four minutes left.

Coming out of a timeout, Elliott fired from deep, hitting what head coach Bob Williams called “the biggest shot of the game.“ It gave the Gauchos a lead and some momentum they would need to stave off the Crenshaw curse and seven more of his points.

The season-long Gauchos’ strength, making free throws, served them well again down the stretch, as senior captain Alex Harris nailed four, Justin Joyner two more, and James Powell a final pair.

“I’m very confident with our free-throw shooting late in games,” Williams said. “It just wins us games.”

Winning games is No. 1 on the Gauchos’ agenda. With three losses, they can afford no more if a conference crown is the target. And it is. They needed this one, and must have two more home wins Saturday against UC Irvine and next Thursday against Cal Poly.

Williams said that to “keep our destiny in our hands, we have to win these games. We can’t afford a slip.” That will give UCSB a chance to get revenge at Pacific on Feb. 20 and then deal Cal State Northridge its third loss when they meet in early March, and make their bid for the title.

They are playing well enough to do it. This game was one of their best.

Paul Roemer had a great game at guard, with five assists, no turnovers and two rare blocked shots. He brought down the house in the first half when he turned on the afterburners and outran a Titan to snag a sure breakaway layup pass.

Harris is healthy and led all scorers with 24. Powell (14) dished off five beautiful assists to go with his consistent point production. Elliott posted his career-high 22 points, and Nedim Pajevic (nine) and Chris Devine (eight) are as strong inside as anyone. And at point guard, Joyner, is running the energetic show superbly.

They are all clicking … right on time.

And if this hard-fought season is to turn out as they hope, they need to be.