AUSTIN, Texas — The day began with a bomb threat that forced the evacuation of the University of Texas campus.

When the Illinois volleyball team was allowed to make its way into Gregory Gym later Friday, it made the most of its opportunity against the nation's sixth-ranked team.

Fueled by Jocelynn Birks' swing and Liz McMahon's block, the No. 23 Illini outbattled the Longhorns 18-25, 25-21, 25-21, 19-25, 15-13 on the opening day of the Texas Invitational.

The victory evened the Illini's record at 4-4 and improved their mark against ranked opponents to 2-3. Illinois will try to rise above .500 for the first time this season today when it faces Central Florida (3-7) at 9 a.m. The Illini conclude tournament play at 7 tonight against Cincinnati (2-8).

Texas (6-3) entered as the nation's top blocking team, but Illinois outdid the Longhorns in that category by a 16.5-12.5 margin.

McMahon, a sophomore right-side hitter, matched her career high with 11 block assists to lead the Illini defense at the net. Senior middle blocker Erin Johnson contributed nine blocks, including one solo, and sophomore middle blocker Anna Dorn added seven block assists.

Birks, a redshirt freshman outside hitter, produced a match-high 21 kills along with 12 digs for her first career double-double.

In the decisive fifth set, the Illini quickly built leads of 4-1 and 5-2, Then Texas responded with a 4-0 run, with Haley Eckerman belting two kills, to force Illini coach Kevin Hambly to call a timeout.

From there, the teams engaged in a tug of war that produced seven ties, the last at 12-12. That's when Illinois' block again came to the rescue. First McMahon and Johnson, and then setter Annie Luhrsen and Johnson combined on blocks to give the Illini a 14-12 lead.

After the Longhorns fended off Illinois' first match-point opportunity with a kill by Sha'Dare McNeal, Illini outside hitter Ali Stark ended it with her 12th kill.

Illinois won despite being outhit .241 to .194 and trailing the Longhorns in digs 64-61. Illini junior libero Jennifer Beltran produced a match-high 28 digs — eight more than her previous season high.

Besides her blocking, Dorn was a force on the attack. She finished with 12 kills — one short of her career high — in 17 errorless swings while hitting a career-high .706.

Luhrsen had a season-high 52 assists and accounted for three of Illinois' eight service aces.

In the pivotal fourth set, Illinois jumped to a 4-1 lead and never trailed until Texas nudged ahead 14-13. The Illini held their final lead at 17-16 after a service error by Texas' Haley Eckerman.

But the Longhorns immediately answered with a 7-0 run, including three service aces by Kat Brooks, to take control and ended up outscoring Illinois 9-2 down the stretch to force a fifth set.