IRVINE — First it was the uniforms, then two-thirds of the lineup. But after the top-ranked UC Irvine men's volleyball team fell for a second straight night to No. 2-ranked BYU, it is change on a fundamental level that is forthcoming for the Anteaters.

Following up a sweep on Friday, the Cougars (4-1, 2-0 in conference), prevailed, 25-22, 25-19, 15-25, 20-25, 15-9, to thoroughly establish themselves as the top team in the nation, as well as the Mountain Pacific Sports Federation.

"They are better than we are," UCI Coach John Speraw said flatly. "For the most part, they pass better than we do and they dig more balls and they block more balls. They hit with greater range and they do a better job of setting. So I think we have a long, long way to go."

Speraw said closing the gap may take nothing short of a revolution.

"We have to change the way we play the game," said Speraw after BYU hit .529 in the fifth set and .406 for the match while posting a 12.5 to 7.5 advantage in team blocks. "I have to totally reevaluate what we're doing as a team, because of the likelihood that we'll have to play BYU at BYU [in the MPSF Tournament].  I've got to reevaluate the way we train because you've got to train very differently if you are going to prepare a team that is going to win at altitude. That is going to change the way we do things for the rest of the year."

Dramatic change occurred even as BYU was capturing its fifth straight game over the Anteaters, who switched to blue uniforms after wearing white on Friday.

By the start of Game 3, UCI (4-2, 0-2) had replaced senior All-American opposite Carson Clark with freshman Zach La Cavera and also added reserves Kevin Tillie, a junior outside hitter, and Michael Brinkley, a freshman libero, to the lineup. Senior middle blocker Dan McDonnell also came off the bench to add a spark, as UCI got the season-best crowd of 2,889 revved up and forced a fifth set.

La Cavera finished with a team-best 10 kills and four aces to earn praise from Speraw.

Tillie had eight kills and hit .381, while McDonnell hit .727 while collecting seven kills and adding a team-best three block assists.

Sophomore starting middle blocker Scott Kevorken hit .643 while producing nine kills. He also added a pair of the 'Eaters' 14 aces.

Sophomore outside hitter Jeremy Dejno (eight kills and three aces) and sophomore setter Daniel Stork (50 assists and a team-high 10 digs) were the lone starters to remain on the court throughout.

UCI, which hit .000 in the second game, wound up hitting .336 as a team.

BYU, which lost to UCI in four games at a tournament on Jan. 6, was led by senior opposite Robb Stowell (21 kills and a .472 hitting percentage) and sophomore All-American Taylor Sander (18 kills, .452).

Middle blocker Russ Lavaja had seven kills and a team-best six block assists, while senior setter Joe Kauliakamoa had 51 assists and a key dump kill that put BYU up, 8-5, in the fifth set.

"We did some different things and they were effective," Speraw said of the lineup changes Saturday. "It's nice to see our team can make some changes in the middle of a match. But ultimately, we still aren't executing game plans like we need to and we still have so much room to improve."

UCI returns to action Saturday at home against UC San Diego, which beat the Anteaters at Bren Center in 2011.

barry.faulkner@latimes.com

Twitter: @BarryFaulkner5