PITTSBURGH — Quarterback Greg Cross scored a 17-yard touchdown on his first-ever collegiate touch to stake Pitt to an early lead, and Pitt’s defense stepped up when it had to as the Panthers held on to beat Iowa 21-20 on Saturday at Heinz Field.

Despite allowing 361 yards, Pitt’s defense answered the call when it mattered most.

“The most encouraging part was the end where we had to make some plays,” Pitt coach Dave Wannstedt said. ‘Two series right before the half, our defense stepped up and got two three-and-outs. Then, at the end of the game, the defense stepped up.”

The big question leading up to the game was whether Pitt’s undersized defensive front could compete in the trenches with a big, physical Iowa offensive line.

There were no doubts after an impressive fourth quarter.

With 4:12 left in the game, Iowa (3-1) took the ball at its 20-yard line, trailing 21-20. On third-and-five from the 25, quarterback Jake Christensen found Brandon Myers wide open in the middle of the field for a 16-yard first-down catch. Two plays later, Iowa faced another crucial third down. In what might have been the play of the game, Pitt’s defensive front was able to flush Christensen from the pocket, and Mick Williams tripped up Christensen for a 7-yard sack forcing Iowa to punt the ball away.

On its ensuing possession Pitt (2-1) quickly went three-and-out. Iowa used all three of its timeouts, and the Panthers were only able to take 25 seconds off the clock.

But Dave Brytus’ 57-yard punt rolled out of bounds inside the 1-yard line. Iowa picked up a first down. On second down, Greg Romeus sacked Christensen. The very next play, reserve end Tony Tucker recorded his first-ever collegiate statistic, forcing a Christensen fumble, and Romeus recovered it, which sealed a big win for the Panthers.

“That fumbled caused was a big play,” Pitt linebacker Scott McKillop said. “Our defensive line, like I said before the game, had to control the line of scrimmage. And I felt in the third and fourth quarter we did a good job of controlling that.”

“We did pretty well, especially towards the end,” defensive tackle Williams said. “We played together and I think conditioning played a big part. We needed this win and we dug down and got it.”

Iowa struck first after LeSean McCoy fumbled on Pitt’s first play from scrimmage, setting Iowa up on the Pitt 16. Trent Mossbrucker connected on a 26-yard field goal, and Iowa led 3-0.

The Cross touchdown run came on Pitt’s ensuing possession.

Lined up in the shotgun, Cross took a direct snap and ran up the middle, bounced it outside, and broke three tackles on his way to the end zone, giving the Panthers their first lead, 7-3. The touchdown was the first that Iowa allowed this year.

On Pitt’s next possession, it faced fourth-and-1 from its own 30. For the second time in the game, Wannstedt opted to go for it on fourth-and-short. For the second time it paid off.

LaRod Stephens-Howling took the handoff around the right edge for a 13-yard gain, and a late hit set the Panthers up on their 8-yard line. Three plays later, Bill Stull did his best Cross impression, taking a quarterback draw six yards for his first career rushing touchdown, capping a 10-play, 54-yard drive, and giving the Panthers the 14-3 lead early in the second quarter.

Later in the second, still trailing 14-3, Iowa went to work on the ground with its punishing back, 5-foot-11, 235 pound junior, Shonn Greene. Greene found a rhythm carrying the ball six times for 52 of Iowa’s 58 yards on the drive. On third-and-three from the 6-yard line, Greene rumbled up the middle to pull the Iowa within four at 14-10. Greene went over 100 yards rushing for the fourth time this season. In the loss, Greene set career-highs in carries (23) and yards (147).

Iowa reclaimed the lead in the third quarter.

On third-and-two from the 20-yard line, Christensen’s pass fell incomplete in the back of the end zone, but Iowa went for it on fourth down and Greene kept the drive alive with a first-down run. On the next play, Greene plowed down to the 2. From there Christensen rolled right, pulled the ball down, and gave Iowa the lead for the first time since the 10:35 mark in the first quarter. The extra point made it 17-14.

Pitt answered with its most impressive drive of the season. Trailing by three headed into the fourth quarter, Pitt orchestrated a nine-play, 80-yard drive that was capped by a 27-yard McCoy (18 carries for 78 yards) touchdown run that gave the Panthers the lead for good, 21-17.

“That was awesome to see that guys stepped up and made big plays (on the drive),” Stull said. “We were going to run our power game and hit them in the mouth and keep hitting them in the mouth. And we definitely did that.

“Our defense played a heck of a game all day. Our defense definitely deserves a lot of credit. To go against a Big Ten team, not many people thought that we could do that. It was definitely a momentum builder headed into next week against Syracuse.”