ERIE — Leading by 13 points at halftime Saturday, Slippery Rock University was poised to complete a perfect run through the PSAC West this football season.

Then it experienced a Knight-mare.

During the first 22 minutes of the second half, Gannon ran off 36 plays to SRU’s 12, took advantage of three Rock turnovers and a muffed punt, scored 26 straight points and held on for a 33-27 victory.

“Once a young team seizes momentum, crazy things can happen,” Golden Knights coach Jim Kiernan said.

Rock coach George Mihalik agreed — to a degree.

“Veteran teams are supposed to be able to grab that momentum back,” Mihalik said.

Not on this day.

The Rock (8-2, 6-1) imploded during the second half after building a 17-0 lead in the game’s first 20 minutes. SRU had the football for 20-plus minutes in the first half.

Gannon (4-6, 3-4) possessed the ball for 20-plus minutes in the second half.

The loss forces The Rock to share the PSAC West title with California — a 34-28 winner over Edinboro — and may affect its bid for a Division II national playoff berth.

SRU travels to Kutztown for the state title game Saturday.

“We definitely need to win there, then wait and see what happens,” Mihalik said.

Trailing 20-7 at intermission, Gannon took the second-half kickoff and marched 78 yards in 11 plays. Lawrence Coleman’s second of three touchdown catches — this one a 6-yarder — capped the drive.

Coleman set the Gannon single-season record with nine TD receptions. The Golden Knights honored 17 seniors before the game.

“This was Senior Day and it was definitely a senior’s day for him,” Kiernan said.

The Rock handed Gannon 45 yards in penalties during that drive, including a facemask call and two pass interferences.

“That opening possession set the tone for the entire second half,” Mihalik said. “We take three major penalties, then it was mistake after mistake after mistake.”

The second of four Daniel Tapscott TD passes tied the game with 7:06 left in the third quarter, but the Golden Knights botched the hold on the PAT and failed to take the lead.

Jimmy Zubik muffed a punt that Gannon recovered at The Rock 25, setting up a 25-yard field goal for the go-ahead points with 13:21 to play. A Cody Endres interception three plays later gave the hosts possession at the SRU 20, setting up a 23-yard field goal.

The Rock fumbled a snap on the next play. Tapscott found Coleman for a 22-yard TD strike moments later and it was 33-20 with 8:25 remaining.

“I wasn’t going through my progressions the right way,” said Endres, who threw three picks in the second half. “This loss is on my shoulders.

“Those kinds of mistakes, forcing our defense to be on the field all the time ... that stuff can’t happen.”

Endres did lead The Rock on a 12-play, 62-yard drive later in the fourth period. He hit Freeport graduate Derek Durand for a 13-yard touchdown after finding Mike Bongivengo for 18 yards on a fourth-and-15 play to keep the drive alive.

Bongivengo and Durand were playing for John Schademan and Kevin Sanders, who were both injured earlier in the day.

“We have depth at the wide receiver position and we needed it today,” Mihalik said.

SRU got the ball back with 2:42 left, but never got out of its own territory.

Endres threw for 272 yards and has now thrown for a school-record 2,318 yards this fall. His 201 completions in 335 attempts this year are also SRU records.

But he didn’t feel much like celebrating as The Rock’s six-game winning streak was snapped.

“We had forgotten how much we hate to lose,” Endres said. “We’ll remember it now.”

Notes: Devin Goda had nine catches for 131 yards, giving him 69 for 961 on the year. ... Brandon Watters recorded his seventh interception of the year for The Rock. ... Zach Sheridan and Jayson Nickson had 12 tackles each for SRU.Gannon 33, SRU 27

Slippery Rock 7 13 0 7 — 27Gannon 0 7 13 13— 33SRU G23 First Downs 2131-112 Rushes-Yards 39-136272 Passing Yards 18822-49-3 Passes (Comp.-Att.-Int.) 13-33-2384 Total Yards 3242-2 Fumbles-Lost 0-06-59 Penalties-Yards 6-85

First QuarterSRU — Devin Goda 15 pass from Cody Endres (Kurt Brackman kick), 11:36

Second QuarterSRU — Jimmy Zubik 2 run (Brackman kick), 14:17SRU — Brackman 24 field goal, 9:35G — Lawrence Coleman 11 pass from Daniel Tapscott (Matt Szczupakowski kick), 4:12SRU — Brackman 31 field goal, :00

Third QuarterG — Coleman 6 pass from Tapscott Szczupakowski kick), 10:28Gannon — Evan Twombly 11 pass from Tapscott (run failed), 7:06

Fourth QuarterG — Szczupakowski 25 field goal, 13:21G — Szczupakowski 24 field goal, 9:33G — Coleman 23 pass from Tapscott (Szczupakowski kick), 8:25SRU — Derek Durand 13 pass from Endres (Brackman kick), 5:52

Individual StatisticsPassing: SRU, Cody Endres 22-49-272-3. Gannon, Daniel Tapscott 13-33-188-2.

Rushing: SRU, Jimmy Zubik 17-50, LaQuinn Stephens-Howling 8-41, Cody Endres 6-21. Gannon, Jansen Jones 29-128, Daniel Tapscott 2-9, Alex Papson 6-4, Team 1-(-2), Everett June 1-(-3).

Receiving: SRU, Devin Goda 9-131, Mike Bongivengo 3-39, Ken Amos 2-31, Derek Durand 2-28, LaQuinn Stephens-Howling 2-17, John Schademan 1-15, Geron James 1-11, Josh Gardner 1-3, Jimmy Zubik 1-(-3). Gannon, Lawrence Coleman 6-92, Jonathon Jones 2-35, Evan Twombly 2-31, Justin Caliste 1-25, Fanny Giegerich 1-3, Jerry Smith 1-2.