Clark, who matched Tillie's four aces (though both had six of the 'Eaters' 22 service errors), hit .447 with four errors on 38 swings. He also added two block assists and five digs as UCI extended its winning streak to seven matches.
The Bruins, whose imposing net presence is heightened by 6-foot-9 senior setter Kyle Caldwell and 6-8 middle blocker Weston Dunlap, both Newport Harbor High products, had won six straight coming in, all sweeps. The hosts, whose legendary Coach Al Scates has won 19 NCAA titles in his 50th seasons but will retire after this one, were also 7-0 at home until Saturday.
UCI, which beat the Bruins in four games at the UCSB Tournament on Jan 8, is now 6-0 on the road this season as it continues to bounce back from early conference home losses to BYU (twice) and Stanford.
The Anteaters avenged that loss to Stanford by topping the Cardinal on their own floor on March 3.
UCLA will visit Irvine on March 31 for an MPSF rematch at Crawford Court.
Beating UCLA, where UCI Coach John Speraw both played and was an assistant coach, created an overflow of postgame text messages on Speraw's cell phone.
"UCLA is a great team that's unique in our league with some of its skill sets and attributes," Speraw said. "Those attributes put a lot of pressure on teams and they challenge you to adapt in the middle of a match, because it's difficult, if not impossible, to simulate in practice."
Speraw cited the play of Clark and his team's ability to win the serving and passing battle for helping overcome UCLA's 18.5-6.5 advantage in team blocks.
"It's a huge win for us," Clark said. "They are probably the best blocking team in the nation and it can be uncomfortable to play against them. Lots of teams struggle against that block, but we were able to grind through it, figure it out and adapt."
Tillie hit .333 with five digs and came up big in the final set. His kills broke Game 5 deadlocks of 9-9 and 10-10, then put the visitors up, 12-10, Tillie also had the match-ending kill.
Senior middle blocker Dan McConnell had eight kills and hit .375, while adding a team-best three block assists for the winners, who received 56 assists from junior Chris Austin.
Austin, making his sixth start after initially relieving Daniel Stork following a concussion, is now 6-0 and, like his team, continuing to grow.
Freshman libero Michael Brinkley led UCI with 14 digs, while Scott Kevorken and Jeremy Dejno had six kills apiece.
Caldwell had 44 assists, three kills, five block assists and 11 digs for UCLA, for which Dunlap added seven kills, three block assists and a .429 hitting percentage.
Jeremy Casebeer, a former Santa Barbara High teammate of Clark, led the Bruins with 12 kills.