You sense Chris Hughton will have declared this latest fact-finding mission a qualified success after guiding the Canaries into the Capital Cup third round.

Rare progress in knockout football was the headline story, but the City chief will also have learned plenty more about his men on the fringes.

Norwich were sluggish in an opening period lit up by Simon Lappin's and Mark Duffy's superb long range efforts. The hosts improved markedly after the interval and in the end were good value for their place in the draw later this week.

Hughton delivered on his pre-match pledge to test the depth of his squad with a complete overhaul from the weekend's Premier League draw against QPR. There was no place for Alexander Tettey with club officials still awaiting international clearance for the Norwegian international midfielder.

David Fox made a welcome return to the fold after a pre-season heavily disrupted by a knee problem. The cultured midfielder slipped seamlessly into a screening role in front of the back four with skipper for the night Wes Hoolahan operating in an advanced position tucked in behind Steve Morison and Chris Martin as Hughton gave the front pair another chance in the wake of their late introduction at the weekend. City's substitutes' bench had frontline experience that numbered Grant Holt and Simeon Jackson alongside the likes of John Ruddy and Russell Martin.

Scunthorpe counterpart Alan Knill included well-travelled midfielder David Prutton in his reserve list after sealing an initial three-month loan move from Sheffield Wednesday earlier in the day.

The League One underdogs displayed few signs of early nerves with Declan Rudd called into action barely two minutes into the tie when Mike Grella burst through City's midfield to slip in Andy Barcham who twisted his way past George Francomb, but the young keeper stood firm at his near post. Martin's industry on the edge of the visiting penalty area fashioned a sharp opening for Hoolahan but his left footer brushed Christian Ribiero. The recalled Michael Turner then threw himself into a ruck of bodies to try and connect with Fox's opening corner, but the Iron's massed ranks crowded out the former Hull man.

Martin looked particularly keen to make an impression on his watchful manager patrolling the touchline with an intelligent early move and cross on the turn from Francomb's throw before an ambitious overhead kick drifted wide of Sam Slocombe's far post.

Morison's nuisance value allowed Martin to slip in unattended in the 15th minute, but a weak intended set up for Lappin gifted Christian Ribiero an opportunity to nullify the growing threat. Hoolahan's exquisite crossfield ball drifted into the path of Morison who fed chief support Marc Tierney but Scunthorpe manfully cleared their lines. Hughton's men were showing signs of easing into their attacking stride after Grella's initial warning shot with Hoolahan a predictable focal point in a freer role roaming across the Iron's backline.

Knill's outfit, however, remained admirably committed to their passing principles despite City's growing threat with Jimmy Ryan setting the metronomic tone. Tierney launched into a clearing challenge but required minor treatment midway through the opening period – the cue for an impromptu drinks' break and coaching session for the visitors.

Hoolahan's harassment of Ribiero sparked the game back into life after a temporary lull only for Lappin's mis-control to release the pressure around the Iron's penalty area. The Scot more than made amends seconds later when he lashed past Slocombe from fully 25 yards after Andrew Surman's penetrative burst and slip pass teed up his midfield ally.

Scunthorpe were back on terms from their first meaningful foray after the restart with a goal every bit as breathtaking as Lappin's opener. Duffy's long range howitzer thudded against the inside of Rudd's left-hand post and over the line – much to the delight of the hardy band of away travellers. The impish Duffy was then quick to snaffle Tierney's miscued header to trigger another counter, but the alert Francomb intercepted his intended ball for Grella.

Ryan Bennett's far post header dropped a yard wide with the hosts probing to restore their lead five minutes before the interval when he rose well under pressure to meet Surman's deep corner.

The former England U21 international then showcased his range of passing skills with a raking diagonal that Morison was unable to control a yard inside the Scunthorpe area. Hoolahan's touch was far more assured when he ran off the back of Riberio to tee up Morison who serviced Surman to whip in a delicious cross which Slocombe initially spilled only for Riberio to bail out his keeper.

If the message from inside the home dressing room at half-time was to re-emerge with greater urgency, Lappin was certainly attuned to Hughton's wishes with another advanced raid producing the first strike blocked by Dave Mirfin after Surman freed the overlapping Scot.

The Scot's urge to carry the fight, however, ended with Lappin's exit from the action after appearing to go over on his left ankle – Anthony Pilkington's arrival triggering a positional switch for Surman to the left flank.

City edged back in front on 55 minutes when Niall Canavan completely wiped out Hoolahan inside the Iron penalty area after the Irishman had latched onto Morison's weighted ball. Norwich's skipper composed himself before lashing past Slocombe from the spot.

Scunthorpe's response to adversity was again admirable. Bennett needed to take emergency action with Duffy lurking behind him from Grella's dipping cross. Rudd's reflexes foiled Duffy in the 64th minute as Knill's side continued to threaten before the City keeper dropped on Grella's swivelling effort. Rudd was then forced to berate the men in front for allowing Ryan a speculative strike.

Francomb scuffed wide at the opposite end after Hoolahan, Surman and Pilkington had sliced through Scunthorpe's midfield with a barrage of sharp passes during City's most productive spell of possession during the tie.

Hughton's men were shocked out of their collective comfort zone when the newly-arrived Rudd had to tip Prutton's acrobatic volley over from 25 yards.

Hughton's side were able to re-establish a measure of control in the closing stages and had genuine appeals for a fresh penalty claim waved away when Martin tumbled under Tom Newey's challenge.