NORMAL — Complete collapse or utter domination, take your pick.

But if anyone saw the second half of Saturday's Missouri Valley Football Conference game at Hancock Stadium coming, he was likely wearing purple.

No. 15-ranked Western Illinois quickly erased a 14-0 halftime deficit and never relented on No. 12 Illinois State while storming to a 31-14 victory before a Family Day crowd of 13,192.

“Offensively, we were not able to sustain a drive the third quarter to give our defense a lift,” ISU coach Brock Spack said. “Then the special teams gaffes. Roll that up in a nice, big package and it leads to a loss.”

In the rivalry's 100th game, Western (6-3, 3-3 in the MVFC) snapped a seven-game losing streak to the Redbirds (6-3, 4-2).

“I know how hard they are to beat, and I know how hard they are to beat here,” said Leathernecks coach Charlie Fisher. “A huge tip of the hat to our players to play that way the second half against a very good football team.”

Western went right to work after receiving the second-half kickoff, marching 78 yards in just three plays for its first points.

A 37-yard pass from Sean McGuire to Tony Harper set up a 35-yard touchdown toss to Brandon Gaston. The Leathernecks chopped their deficit in half a mere 1:18 into the third quarter.

“We had a great halftime locker room,” McGuire said. “We said when we stepped on the field the whole game was going to change. Our mind was in the right spot. We’ve come back so many times, there’s not ever a need for panic.”

Western was more deliberate but just as effective on its next possession. A 1-yard Clint Ratkovich touchdown plunge was the final snap of an 11-play, 89-yard journey. McGuire connected with Jaelon Acklin for 26 yards on third-and-2 at the Redbird 27.

“There were some plays to be made out there, and they made the plays,” ISU safety Mitchell Brees said. “They were just a good offense the second half, and we could have done some things better.”

Western assumed a 17-14 lead when Sam Crosa nailed a 28-yard field goal on the final play of a third quarter in which the Leathernecks outgained the Redbirds, 209 yards to 36.

“Football is a game of momentum. You’ve got to seize it, keep it and build on it,” said Fisher. “We were able to do that the second half.”

Spack felt the tide of momentum turning and sought to regain it with a fake punt. But Jordan Birch was stopped for a 1-yard loss on fourth-and-7 inside the ISU 30.

“We had the look we wanted. Maybe we shouldn’t have put a young player in position to make a decision,” Spack said. “He went up field and should have gone inside. But 20-20 hindsight, we probably shouldn’t have done it.”

Western then made it three straight huge plays. First, McGuire appeared to overthrow Clint Ratkovich, who made a spectacular, sprawling catch of a 27-yard touchdown pass that held up to replay review.

Then the Leathernecks crunched Markel Smith on the ensuing kickoff and recovered the Redbird fumble at the 20.

The visitors’ advantage would soon swell to 31-14. Two plays after McGuire converted third-and-13 with an 18-yard pass to Gaston, Steve McShane covered the final yard into the end zone with 9:56 remaining.

“We didn’t do anything right the second half offensively. We couldn’t sustain a drive and keep our defense off the field,” said ISU quarterback Jake Kolbe. “We didn’t bring enough energy out. They made some plays on defense, took away some things and got some pressure.”

ISU surged to a 14-0 lead for the third straight game.

The Redbirds' first scoring opportunity was snuffed out on an interception in the end zone, but Kolbe rebounded with a perfectly thrown 65-yard touchdown pass to Christian Gibbs behind the WIU defense.

ISU grabbed a 14-0 margin with 6:43 left in the second quarter on the first touchdown reception of Tylor Petkovich's career. The tight end hauled in a 4-yard strike from Kolbe in the back of the end zone.

Kolbe completed 19 of 34 passes for 223 yards, while James Robinson’s 73 yards on 16 carries led the Redbird ground game.

McGuire passed for 288 yards, while completing 19 of 30. Western compiled 281 of its 406 yards of total offense after halftime.

Follow Randy Reinhardt on Twitter: @Pg_Reinhardt