Downers Grove South boasts 30 playoff victories in its storied football history, but no current player knew what it felt like until Saturday night.

The Mustangs won their first postseason game since 2005 with a 22-21 victory over Waubonsie Valley in a first-round Class 8A matchup at Lisle's Benedictine University.

"First playoff win for us in a few years, and coach (John Belskis) was always saying that he can't explain the feeling to us," said Mustangs quarterback Chandler Whitmer. "It's a great feeling right now."

Trailing 21-12 in the fourth quarter, seventh-seeded Downers South (8-2) rallied with Mike Ficaro's 29-yard field goal and a 5-yard touchdown pass from Whitmer to Dan Miller with 4:23 left.

Tied 21-21, Ficaro nailed the extra point to put the Mustangs ahead 22-21 - a critical play after Downers South failed to convert an earlier extra point and 2-point pass.

Tenth-seeded Waubonsie Valley (6-4) then drove 56 yards in 11 plays, setting up a 40-yard field-goal attempt by Scott Kuehn with 28.8 seconds left. The kick went wide left, preserving a tough victory for Downers South.

Next up is a rematch at No. 2 Bolingbrook, which beat Downers South 16-14 in the season opener.

"It was a well-played, back-and-forth football game," Belskis said. "We're excited about the win and going back to Bolingbrook."

The teams traded dominant quarters in the first half. Downers South built a 12-0 lead on Whitmer touchdown passes of 10 and 21 yards to Jason Jozaites, who had 9 catches for 150 yards.

Waubonsie Valley stormed back in the second quarter, exploding for 21 straight points. After a 2-yard touchdown run by Tyree Dickerson, Kenny Clay threw a 25-yard touchdown pass to Malcolm Buckner.

Warriors linebacker Cory Connolly snared an interception on the next play from scrimmage, setting up Clay's 16-yard touchdown pass to Eric Josupait just before halftime. But after rolling up 159 yards, 10 first downs and 3 touchdowns in the second quarter, Waubonsie Valley's offense went silent for most of the second half.

"In the first half we were on the attack," Clay said. "In the second half we didn't have that same swagger, except on the last drive."

Whitmer completed 15 of 23 passes for 147 yards while Clay completed 12 of 16 passes for 147 yards. The Mustangs' Josh Williams rushed for 73 yards. Dickerson ran for 60.

"We've got nothing to be ashamed of, nothing to hang our heads about," said Warriors coach Paul Murphy. "We just weren't as aggressive as we should have been in the second half."