UNIVERSITY PARK, Pa. -- With its offense struggling and its special teams imploding, Penn State turned to its defense once again.

Outside linebacker Navorro Bowman snapped a third-quarter tie yesterday by intercepting a pass and returning it 73 yards for a touchdown as the Nittany Lions rallied to beat Indiana, 31-20.

Bowman's touchdown was his second of the season -- he returned a fumble 91 yards for a score against Eastern Illinois -- and it proved to be the turning point in No. 19 Penn State's victory on Senior Day at Beaver Stadium.

"That was huge," outside linebacker Sean Lee said. "That was the difference."

Five weeks ago, Bowman nearly ran out of gas before reaching the end zone.

Yesterday, after Indiana quarterback Ben Chappell fell down near midfield, Bowman was home free. He picked off the screen pass at the 27 after Hoosiers tailback Trea Burgess tipped it in the air.

"It was a big boost for us," said Bowman, a redshirt junior who is considering bypassing his final year of eligibility to enter the NFL draft.

"It got us the lead, and we didn't look back."

Bowman's big play not only helped the Nittany Lions (9-2, 5-2 Big Ten) improve to 13-0 all time against the Hoosiers (4-7, 1-6), it took some of the heat off of the team's horrendous special teams play.

The Lions, ranked 107th or worse among 120 Division I-A teams in four special teams categories, lost two first-half fumbles on punt returns by Drew Astorino and Graham Zug.

Zug also fumbled another punt that he recovered, but the play was negated by a 15-yard penalty against Indiana for kick-catch interference.

"We debated whether or not to take Zug off the punt-return team," coach Joe Paterno said, "and I told him at halftime, 'If you have the moxie, go out there and forget about a couple of mistakes and catch the football.' "

Shortly after Paterno uttered those words in the locker room, Jerome Hayes fumbled the second-half kickoff following a 35-yard return. Penn State's James Van Fleet recovered. Then, Collin Wagner missed a 34-yard field-goal attempt, banging it off the right upright.

The loudest cheer of the day occurred when Zug held onto the ball after making a fair catch in the third quarter.

"It was definitely a frustrating day for the special teams," Zug said.

Senior quarterback Daryll Clark was not sharp, either. He threw two first-quarter interceptions and finished 17 of 28 for 194 yards and a touchdown in his final home game.

Penn State lost three key players to injuries: cornerback A.J. Wallace (concussion), wide receiver Chaz Powell (right shoulder) and tailback-fullback Brandon Beachum (right knee).

Beachum's injury, which occurred on special teams play in the third quarter, very likely will end his season.

"It looks like he has a pretty serious knee injury," Paterno said. "He is probably out."

Wagner kicked a 33-yard field goal in the second quarter and tailback Evan Royster scored the first of his two touchdowns on a 13-yard pass from Clark with six seconds left in the first half to tie the score at 10-10.

Royster, who carried 17 times for 95 yards and caught four passes for 39 yards, also scored on a 2-yard run early in the fourth quarter and Clark added a 1-yard sneak to seal the win with 4:08 remaining.

The Lions finished with 181 yards rushing and 375 yards offense, but Bowman was the star. He finished with a team-leading 12 tackles and one of the team's two sacks as the Lions held Indiana to 48 yards rushing and 346 yards offense.

"Our defense has really been playing well," said Royster, who needs only 10 yards at Michigan State Saturday to go over 1,000 for the second consecutive year.

"A lot of times they have saved us."

NOTES -- Lee, a fifth-year senior co-captain from Upper St. Clair High School, had 10 tackles, giving him five games this season with at least 10. He also had a career-high four pass breakups. ... Wide receiver Derek Moye from Rochester had two catches for 28 yards, but he also had two drops -- one at the goal line and another inside the 5. Clark, who has thrown 10 interceptions this season, also overthrew Moye on another pass play inside the 5. ... True freshman defensive end Sean Stanley had a sack.

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