Iowa State went on a 7-1 run midway through the fifth set to take command against Illinois en route to a match-clinching 15-10 win.
The No. 15 Cyclones defeated No. 19 Illinois 26-28, 25-19, 25-22, 23-25, 15-10.
Iowa State freshman Mackenzie Bigbee, whose kill finished the match, racked up a career-high 25 kills.
Sophomore right-side hitter Liz McMahon led the Illini with 16 kills.
Illinois (2-3) committed 13 service errors, offsetting a commanding 14-6 edge in blocks against Iowa State (2-3).
Liz McMahon produced three of Illinois' final four points to help her team pull out a 25-23 victory in Set 4 and send the match to a decisive fifth set.
Iowa State, which earlier trailed by seven points, cut its deficit to 21-20 before McMahon belted back-to-back kills to give Illinois some breathing room.
The Cyclones fended off set point at 24-20 by scoring three straight points, all on kills by Mackenzie Bigbee. But McMahon again responded, delivering a kill to clinch the win for Illinois.
McMahon had five kills in the set and leads Illiinois with 15.
Bigbee also had five kills in Set 4 and has a math-high 21 kills.
A mistake-prone Illini team was unable to overcome its errors in the third set, losing 25-22 to fall behind two sets to one.
Illinois committed six hitting errors and was guilty of six service errors, give Iowa State almost half of its points in the set.
Illinois never led in the set and fell into a quick 7-1 hole. Iowa State several times built leads as high as seven points and was still ahead 22-16 when Illinois put on one final surge. With Morganne Criswell delivering a kill and and ace, the Illini scored four straight points to cut its deficit to 22-20 and force the Cyclones to call a timeout.
Two kills by Jocelynn Birks kept Illinois with two points, but at 24-22, Jamie Straube belted her nine kill of the match to clinch the set for Iowa State.
Iowa State built a huge early learn and held off a late comeback by Illinois to win the second set 25-19.
Illinois, which never led and managed merely one tie, fell behind 17-6 behind the hitting of Victoria Hurtt and Mackenzie Bigbee. During one stretch, the Cyclones outscored the Illini 10-1, forcing Illini coach Kevin Hambly to burn both of his timeouts for the set.
Illinois still trailed 22-14 when it scored four straight points, capped by a block by Jocelynn Birks and Anna Dorn. But Iowa State scored three of the next four points to clinch the set.
Bigbee belted nine kills in 12 swings during the set and have a match-high 13 kills. Hurtt contributed five kills in the set and has seven for the match.
Iowa State outhit Illinois .300 to .161 in the second.
Liz McMahon leads the Illini with eight kills.
Illinois withstood a late rally by Iowa State and pulled out a hard-fought 28-26 victory in the first set.
The Illini twice led by as many as seven points, at 19-12 and 20-13, and were on the cusp of clinching the set at 24-19. But Iowa State then rattled off five consecutive poinits, tying the score at 24 on a kill by Tenisha Matlock.
Illinois fought back, twice serving for set point but unable to convert. On the Illini's third set-point opportunity, at 27-26, setter Annie Luhrsen found the floor with her second kill to clinch the victory.
Liz McMahon led the Illini with five kills in 10 swings, while Morganne Criswell added four kills in eight attempts.
Each team's attack was clicking, Iowa State hitting .366 and Illinois hitting .357.
Welcome to our live report from Huff Hall on the second day of the Illini Classic.
The No. 19 Illini and No. 15 Iowa State will conclude the tournament today with their second matchup in as many days. Illinois, in by far its most impressive performance so far this season, rolled to a 25-16, 25-22, 25-16 victory against the Cyclones on Friday night in front of the 10th largest volleyball crowd in Huff Hall history -- 3,770.
The win evened Illinois' record at 2-2, the first time it has reached .500 this year. Iowa State enters 1-3.
Led by sophomore outside hitter Morganne Criswell's .500 attack percentage in 20 swings, the Illini hit a season-high .343. Iowa State committed 24 hitting errors and hit .096.
Illini coach Kevin Hambly said after the match that he fully expected the Cyclones to be better today, "and we need to be better," he added.
Since this is a two-team tournament consisting of two matches, I just asked UI sports information assistant Mike Koon how the champion would be determined? Would the title be shared if Iowa State won today? Would there not be a champion? He said he was unsure. We'll try to get more info on that.
If a champion is declared, and if it is Illinois, this would be the Illini's seventh straight title in their own tournament.
We'll update today's match after each set, so be sure to check back in.