The Hawkeyes (5-3, 2-2 Big Ten) nearly blew another game after leading at halftime. Northwestern (4-4, 0-4) dropped its fourth straight game.
Rudock completed 19-of-27 passes for 169 yards -- none bigger than the third-down pass to Fiedorowicz in overtime. Rudock rolled to his right and lofted a pass to his big tight end in the left corner of the end zone.
Northwestern's Kain Colter was sacked on the final play of the game to seal the win for the Hawkeyes.
Iowa snapped a two-game losing skid. The Hawkeyes led at halftime in each of their three losses.
Colter returned for the Wildcats after missing last week's game against Minnesota with an ankle injury. Penalties and Iowa's stingy defense ruined his return.
The Hawkeyes recorded a season-high six sacks. Iowa recovered two fumbles and totaled 12 tackles in the backfield.
Both teams made mistakes on key opportunities late in the fourth quarter.
Iowa's Mike Meyer pushed a 42-yard field goal to the left of the uprights with five minutes left.
Northwestern's ensuing drive ended after four plays when running back Mike Trumpy mishandled an option pitch from Colter with three minutes left.
The Hawkeyes might have had a long field goal shot in the final minute but a Rudock pass was tipped and caught by an offensive lineman, forcing Iowa to go for it with 15 seconds left. Rudock's attempt was intercepted.
The Wildcats scored 10 unanswered points in the second half to tie the game.
Colter connected with tight end Dan Vitale on a 10-yard score with 4:44 remaining the third quarter. After Colter's play-action fake he found Vitale wide open in the middle of the end zone.
Northwestern put together an 8 1/2-minute drive later in the half, but the Wildcats were forced to settle for a Jeff Budzein 29-yard field midway through the fourth quarter.
Running back Damon Bullock's 3-yard touchdown run gave Iowa an early lead after its opening drive.
Mike Meyer kicked a 38-yard field goal to make it 10-0 Hawkeyes. The kick moved Meyer into second place on Iowa's all-time field goal list.
Colter looked sharp for Northwestern. The dual-threat QB threw for 104 yards and ran for 60 yards. He completed 11-of-14 passes.