Teemu Pukki could have just padded out Norwich's lead in some style.
He tries a dinked shot over Preston keeper Freddie Woodman but his effort goes wide of the post.
Portsmouth have been pegged back by Fleetwood at Fratton Park.
Josh Koroma gave the hosts the lead after seven minutes but Carlos Mendes Gomes has levelled the scores eight minutes later.
With in-form Barnsley behind to Exeter at Oakwell, Sheffield Wednesday are the only team in the top-six to lead at this stage.
Elsewhere Greg Taylor has turned into his own net to give struggling Bristol Rovers the lead at home to Cambridge.