BLOOMINGTON, Ind.—Dan Persa and the Northwestern offense confounded Indiana all day – even when Persa wasn’t making things happen.The junior quarterback threw two touchdown passes Saturday before leaving midway through the fourth quarter with an apparent concussion, and backup Evan Watkins set up a long field goal that helped the Wildcats hold on for a 20-17 victory at Indiana.Northwestern (6-2, 2-2 Big Ten) has now won six straight road games and is bowl eligible for the fourth consecutive season.The reeling Hoosiers (4-4, 0-4) have lost four of their last five overall and nine straight conference games.Saturday’s contest was hyped as a showdown between the league’s No. 1 and No. 2 passing quarterbacks, Ben Chappell and Persa, but Persa clearly outplayed the Indiana senior.Persa finished 18 of 28 for 212 yards and ran 11 times for 19 yards before leaving with 8:53 left in the game.Chappell was 30 of 54 for 308 yards with one touchdown and one interception. He also ran for a score, but he missed receivers high and long most of the day and the Hoosiers’ usually high-scoring offense never got in sync.That’s not how things started, though.Chappell took the Hoosiers 61 yards on their opening possession before settling for a field goal from Mitch Ewald, and the defense forced punts on each of NU’s first three possessions.The Hoosiers appeared to have stopped Northwestern a fourth straight when they finally sacked Persa. But Mick Mentzer’s face mask penalty extended the drive, and three plays later, Persa connected with Jeremy Ebert for an 11-yard TD pass early in the second quarter.Chappell took Indiana on a 16-play, 97-yard drive late in the first half, running the final 5 yards himself and twisting his way into the end zone – a play that stood up to replay review. That gave IU a 10-7 lead with 48 seconds left in the half.It didn’t last long.When Persa scrambled out of trouble on the ensuing possession, he found Mike Trumpy for a 38-yard pass down the right sideline. Two plays later, Persa got away from the pressure again, and Demetrius Fields made a one-handed stab for a 23-yard reception. Fields took the ball to the Indiana 6 with 1 second left, and Stefan Demos made a field goal to tie it at 10.Persa went back to work in the second half. On the Wildcats first possession, he converted on third-and-10 and third-and-2 before beating the Indiana secondary with a perfect 30-yard TD pass to Ebert on third-and-15 for a 17-10 lead.Persa left with 8:53 to go in the game and Watkins’ first completion got the Wildcats into position for a 45-yard field goal that gave NU a 20-10 lead with 6:51 left.Indiana didn’t score again until Chappell’s 39-yard TD pass to Duwyce Wilson with 44 seconds to go.The Hoosiers’ onside kick didn’t go 10 yards, and the Wildcats ran out the clock.Trumpy carried 21 times for 110 yards and Ebert finished with five catches for 98 yards.Damarlo Belcher led Indiana with 11 catches for 87 yards.