The former Manchester United man netted Mirko Slomka's side a vital equaliser after Yoni Buyens and Mohammed Tchite cancelled out Lars Stindl's penalty
Roland Duchatelet's men approached the side with an unhappy record against Bundesliga outfit, but dominated the early proceedings, only to fall behind to a Lars Stindl penalty.
The hosts turned the match on its head soon after, however, with Yoni Buyens and Mohammed Tchite sending their side into a half-time lead, before Mame Biram Diouf tapped home an equaliser just after the break.
The warning signs were evident for Hannover right from the off. Tchite forced a save from Ron-Robert Zieler with an acrobatic effort just minutes in, before the Germany 'keeper was made to punch away a swerving Cyriac effort.
Some good work down the right provided Cyriac with an opportunity in the box, but under close scrutiny from Mario Eggimann, the Ivorian was pushed out, leaving Zieler to make a simple block when the shot finally arrived.
Almost 20 minutes had passed when Hannover finally registered a shot in anger, but Sofian Chahed's effort sailed comfortably wide of Sinan Bolat's goal.
The strike gave the visitors a shot in the arm, however. Konstantin Rausch's charge into the box was halted by a wreckless challenge from Kanu, and Stindl sent Bolat the wrong way from the spot.
Hannover won a corner minutes later, but it was to prove their downfall. Bolat claimed the ball confidently, and wasted no time in releasing Tchite down the right.
The Belgian galloped forward, before crossing to Buyens, who atoned for his earlier miss by flicking the ball into the far corner, beyond the out-stretched arms of Zieler.
It wasn't long before the hosts were ahead. An almost identical move from Standard resulted in Jelle Van Damme's effort being touched behind, but as Serge Gakpe's corner came into the mix, Tchite peeled off Chahed at the near post to head his side ahead.
Pocognoli had to be on his guard to prevent Rausch's cross from reaching the lurking Didier Ya Konan, but the volley of goals proved to be enough for Duchatelet's men to reach the break a goal up.
William Vainqueur registered an effort for the host seconds after the restart, but that was a momentary lapse in Hannover's quest for an equaliser.
Stindl twice shot from distance, forcing a save from Bolat with the first effort, with the other sending the Turk diving across the face of his own goal.
They were not made to wait long for their goal, however. Stindl was at the heart of the move, thrusting into the box, before the ball broke to Didier Ya Konan, who was able to pick out the unmarked Diouf to tap home.
Hannover soon went about trying to restore their lead, with Ya Konan's attempt sailing wide shortly afterwards, but much of the visitors' approach play lacked a sense of finesse, and the final ball was often misplaced.
Ya Konan forced Bolat into the simplest of saves with a tame shot from distance, before Sergio Pinto sliced an effort from distance into touch when he should have tested the 'keeper.
At the other end, Standard had pleas for a penalty ignored as Tchite and Chahed jockeyed for position, while another Tchite bicycle kick was parried wide by Zieler.
Kanu rose highest from Pocognoli's free-kick, flicking the ball goal-wards and forcing Zieler into an acrobatic stop with minutes remaining as the hosts pressed for a winner.
Zieler inexplicably dropped a Felipe header deep into added time, but was able to recover and palm the ball out of danger with Birkir Bjarnason looming.
In the end, though, neither side was able to produce a winner, but having scored two away goals, Hannover will fancy their chances of progression to the next round.