And the left-back believes the club’s “world-class” set-up means their fine form can continue.
Many expected Saints to struggle this term after a summer of upheaval on the south coast, with manager Mauricio Pochettino followed out of the club by a host of key players.
Words such as meltdown and crisis were bandied around, yet Ronald Koeman’s side have made a mockery of such talk with their incredible start to the season.
Southampton will start November second in the Premier League thanks to Saturday’s 1-0 win against Stoke and, while most onlookers are shocked, it comes as little surprise to summer acquisition Bertrand.
“Probably from the outside (you could not have predicted this) when you see a club lose a lot of players and a manager — a manager more so, for me,” the on-loan Chelsea left-back said after Sadio Mane’s strike secured another three points.
“But the people behind the scenes at Southampton have brought in a world-class manager and world-class players.
“As soon as I came in and saw the players, saw everyone training and what they’re capable of, it’s not a surprise to me.
“A lot of people can talk on the outside about how we’re going to finish or what’s going to happen throughout the season, but the only people who can control it is us.
“As long as we keep working hard and doing the right things well, we’re coming out on top at the minute.”
Stoke will not have long to wait to avenge their defeat, given they host Southampton in the Capital One Cup on Wednesday.
Charlie Adam concedes Koeman’s men were the better side at St Mary’s, but he is confident Stoke can make amends at the Britannia Stadium.
“We learn from it and we’ll go again Wednesday night when we play them again in the cup,” the Stoke midfielder said.
“It will be a difficult game but we’re at home and it’s one where we need to go and show something better than we did here.”
SOUTHAMPTON: Forster, Clyne, Fonte, Alderweireld, Bertrand, Steven Davis (Gardos 90), Schneiderlin, Cork (Wanyama 62), Tadic, Pelle, Mane.
STOKE: Begovic, Bardsley, Shawcross, Wilson, Pieters, Nzonzi, Adam (Diouf 53), Walters (Arnautovic 69), Cameron, Moses (Assaidi 79), Crouch.
Referee: Jon Moss.