Sheffield Wednesday survived a scare against Grimsby to book their spot in the Carabao Cup third round with a comfortable 5-1 comeback win at Blundell Park.

Cameron McJannet put Grimsby in front with a header to give the hosts a half-time lead but quick-fire goals from Ike Ugbo and Jamal Lowe turned the tide within the opening 10 minutes of the second half.

A late brace from Callum Paterson extended the visitors’ lead further before Pol Valentin added the gloss at the death.

Chances were few and far between in the opening exchanges, but Grimsby grabbed an opener in the 18th minute when centre-back McJannet rose highest from a Charles Vernam corner to glance the ball past Pierce Charles.

It might have been even worse for the Championship giants heading into half-time, too, had Kieran Green not headed against the crossbar.

Wednesday made two changes at the break and they were rewarded after 53 minutes with two goals inside 90 seconds to stun their League Two opponents.

At first, Ugbo turned into the net after being teed-up by substitute Valentin and the other player who was sent on, Lowe, scored moments later.

Grimsby pushed and probed for a way back into the tie, but Paterson had the definitive say, sweeping past Jake Eastwood twice in the final 20 minutes as Valentin powered home a fifth goal for Wednesday two minutes into stoppage time.