SOUTHERN CALIFORNIA REGIONAL BASKETBALL PLAYOFFS : Mater Dei Showdown Has a Different Look : Division I boys: With Crenshaw eliminated, Clovis West faces Monarchs in Division I regional final tonight.

High school basketball fans anticipating another boys’ showdown between Mater Dei and Crenshaw for supremacy in the Southland were thrown for a loop Thursday night.

Crenshaw, the two-time defending State Division I champion, was upset by Clovis West, 67-62, in the Southern Regional Division I semifinal.

“We entered the game very much in awe of Crenshaw and all its tradition,” Clovis West Coach Vance Walberg said. “We somehow managed to escape with a win, and now we’re just trying to keep our feet on the ground. There’s no time to dwell on the past.”

Clovis West’s reward for its biggest victory in school history is a date with Mater Dei, the state’s top-ranked team, in the Southern Regional Division I final at 8 tonight at The Pond of Anaheim.

Crenshaw defeated Mater Dei in the last two regional finals and the teams figured to meet again after being seeded No. 1 and No. 2.

Although Clovis West has never advanced this far in the State tournament, it has worn the underdog label well. It came back to defeat Fontana, the Southern Section Division I-AA champion, on Tuesday, and used a fourth-quarter rally to knock off Crenshaw, the City Section 4-A titlist.

The Golden Eagles (28-2) will have their hands full with Mater Dei, however, which has won 23 consecutive games and defeated La Puente Nogales by a record 50 points in the Southern Section I-A final last weekend.

“I had a chance to see that Mater Dei-Nogales game and it certainly was intimidating,” said Walberg. “They’re like men among boys. But we’re not going to fold up our tents just yet.”

Walberg and his staff locked themselves in an Orange County hotel room Friday morning to review game film and plot strategy. Although Clovis West is averaging 75 points a game, Walberg said his team’s only chance is to slow the tempo against Mater Dei.

Fairfax used the same strategy Thursday. It led the Monarchs, 18-16, at halftime and 20-18 in the third quarter before collapsing. Mater Dei’s 41-28 victory was a season-low point total and a cause for some concern.

“Maybe it was good for us to be behind,” Mater Dei Coach Gary McKnight said. “It could help us later.”