The Manchester Arena suicide bomber was missed by seconds by a police patrol, the inquiry into the bombing heard.
Salman Abedi, dressed in black and bent over by the weight of the home-made bomb in a large rucksack, later made his way to the foyer where he detonated the explosive, killing 22 people.
The inquiry has heard of "missed opportunities" prior to the attack.
Police personnel patrolling Manchester Arena were also absent from patrol for more than two hours, the inquiry heard.
Four British Transport Police (BTP) operatives were present on the night of the attack, one PC and three PCSOs, patrolling in pairs, the hearing in Manchester was told.
It heard PC Jessica Bullough and PCSO Mark Renshaw took a break at about 19:30 BST, leaving Manchester Arena to buy food, as the Ariana Grande concert began on 22 May 2017.
They returned 45 minutes later and resumed patrolling two hours and 10 minutes after they first departed to buy food, the inquiry heard.
Two more PCSOs, Jon Morrey and Lewis Brown, took an hour's break from 21:15.
Between 21:15 and 21:37, it appeared no BTP officer was patrolling the railway station, when Abedi took up his position at 21:33 in the foyer of the venue, the inquiry heard.
Earlier, the two PCSOs had conducted a routine check on toilets at Victoria Station at 20:49, less than a minute after Abedi left there.
Both police and Showsec security workers later received reports of suspicions from members of the public about Abedi, the inquiry was told.
The inquiry continues.