Kaufman failed to reach 200 yards, but he did have 191 and hauled in three of Kyle Padron's school-record-tying six touchdown passes as the Eagles advanced to the semifinals of the Football Championship Subdivision playoffs.
Second-seeded Eastern (11-2) will stay home to face Sam Houston State on Saturday afternoon.
Padron, a transfer from SMU, connected with Kaufman on back-to-back scoring plays early in the third quarter, and then the duo hooked up again early in the fourth to turn back the Redbirds (9-4), who were 6-0 on the road coming into the game.
"He's definitely a special receiver, one of the best I've had the opportunity to play with," Padron said after completing 19 of 33 passes for 358 yards. "You put the ball in his area, he's going to come down with it."
With a 24-17 lead at the half, Padron dropped a perfect pass into Kaufman's hands at the goal line. Ronnie Hamlin intercepted ISU quarterback Matt Brown on the next play, setting up Padron's 17-yard strike to Kaufman in the back right corner of the end zone for a 38-17 lead at the 11:01 mark.
But the biggest connection came a quarter later, after the Redbirds had scored 18 straight points to close with a field goal.
Facing a third-and-9 on the 24, Padron lofted the ball down the right sideline and the momentum switched.
"It was a little underthrown," Padron said. "He's 6-foot-5, went up and got it, shook off a couple of guys and ran for 40 yards or so. I didn't do a whole lot."
Kaufman, who had his 18th 100-yard game and became the Big Sky Conference single-season record holder with 1,635 yards receiving, said, "It was an overall team effort. Balls are being put in the right places. But right now I have a fight in me I didn't necessarily realize I had."
Padron's last touchdown, a 10-yarder to Ashton Clark with 7:42 remaining, closed the scoring. Quincy Forte, who rushed for 116 yards on just seven carries, set up the score with a 57-yard burst.
Brown was 27 of 48 for 372 yards but had that critical interception, plus another in the final seconds. Tyrone Walker had 148 yards receiving and a touchdown on nine catches, and Lechein Neblett caught six passes for 101 yards and a TD. Darrelynn Dunn rushed for 98 yards and a score to go over 1,000 yards for the season.
"We played hard, we didn't play well at times," Illinois State coach Brock Spack said. "We made too many mistakes to win a game of this magnitude."
After Kaufman's back-to-back TDs, ISU came back with a field goal, a 22-yard Brown-to-Neblett score and Brown's 13-yard TD on a quarterback draw. With a two-point conversion, the Redbirds pulled within a field goal with 13:55 to play.
At that point, EWU had run seven plays for minus-21 yards since opening a three-touchdown lead.
"When you get down to the final eight in the country, you know you're going to go through some highs and lows in the football game," Baldwin said. "That game had a lot of emotion, a lot of momentum swings. Every time it felt like maybe we were losing the momentum, we found ways to make plays again. No one panicked on the sidelines."
The game started out like a track meet, highlighted by a handful of huge plays, before EWU took a 24-17 lead into halftime.
Illinois State opened the game with a long drive that stalled inside the 10, resulting in a Nick Aussieker 23-yard field goal. Eastern Washington responded with Padron's 44-yard scoring pass to Daniel Johnson, who slipped out of the backfield and was wide open down the middle.
The Redbirds answered that with Brown's 40-yard touchdown to Walker. On the ensuing kickoff, EWU freshman Shaquille Hill raced untouched 94 yards for an apparent touchdown, but he dropped the ball at the 2-yard line. The ball bounced into the end zone, but nobody recovered it before a referee touched the ball, resulting in a break for the Eagles first and goal at the 1.
ISU held the Eagles to Jimmy Pavel's 20-yard field goal, his school-record 17th this season.
Josh Burch then returned the EWU kickoff 72 yards, setting up Dunn's 3-yard scoring run in the first minute of the second quarter to put the Redbirds up 17-10.
On the following kickoff, Cory Mitchell went 67 yards, setting up a 1-yard run by Demitrius Bronson that tied the game again.
Then there were four straight punts, with the Redbirds getting the ball on the Eastern 46 after the last one. But three plays later, when Brown hit James O'Shaughnessy for 19 yards, T.J. Lee III stripped the ball, which bounced all the way to the Eagles 6, where Jordan Tonani scooped it up and took it to the 21 with 3:21 left.
Padron put together a 12-play, 79-yard drive highlighted by a third-and-17 conversion on a 25-yard pass to Ashton Clark. Zach Gehring capped the drive with a 1-yard TD reception just before halftime.