In the second minute of stoppage time, McLean showed great composure to pick out Hernandez - who was again allowed to run at Arsenal's defence - and he found academy graduate Cantwell, who slotted into the corner for his fourth goal of the term.
Norwich remain second from bottom with 11 points from 14 games while Arsenal are eighth.
Kenny McLean - 6 - Playing in the hole behind Pukki, the Scottish worldwide wasn't going to be asked twice to venture beyond the Finnish striker if the opportunity arose and it was his pass that led to Norwich's oponer.
Gabriel Martinelli (for Özil 89) - N/A - A late sub.
Man of the match: Bernd Leno.
Arsenal have already begun evaluating candidates for the post, but Kroenke insists they will not rush to make decisions, believing Ljungberg will prove to be an effective manager in the meantime.
After wind scare, balloons fly in Macy's Thanksgiving parade
Handlers kept the giant balloons near the ground, making them more manageable in the wind. "It is the people I love", he said. For the past year, he's been excited to play the Macy's Thanksgiving Day Parade , but he started feeling sick last Friday.
The Swede, who was a crucial part of Arsenal's success in the early 2000s under Arsene Wenger, is very much a modern manager, who puts serious emphasis on wide players, as well as dynamic midfielders.
Arsenal's initial statement on Emery's sacking, though, also confirmed that 'the search for a new head coach is underway', suggesting Swedish tactician Ljungberg is not viewed as a potential answer to the club's long-standing problems in the dugout.
However, that alarming sequence of results came to an end last weekend following a fine 2-0 triumph over Everton at Goodison park.
Ljungberg added: "Pepe is a very good player, but I try to look at what is done in training and what I see every day and that is how I judge it". We dominated totally and that's when we needed a goal. "Let's get to work!" I want this club to do well, it is only winning that counts: I wanted to win the games so I am disappointed but I have also seen some positive things.
The Gunners sacked Unai Emery on Friday after a run of seven games without a win in all competitions.
The Gunners have not won a Premier League match since October 6 against Bournemouth.
Arsenal now host Brighton on Thursday at 8:15 p.m. GMT, before going to West Ham next Monday at 8 p.m. GMT, live on Sky Sports.
Manchester United will be facing Aston Villa on Sunday.