Ole Gunnar Solskjaer warned the rest of the Sky Bet Championship that Cardiff would improve after the Bluebirds climbed into second spot.
Nicky Maynard's second-half goal sunk his former club Wigan to give Cardiff seven points out of nine following relegation from the Barclays Premier League last season.
"It wasn't very pretty and we didn't play anywhere to the potential in the team, but the back five were magnificent," Cardiff manager Solskjaer said after the game.
"We didn't play well and the big thing for me is that I know we can improve.
"We're just happy we have shown we have developed and improved our defending as a unit in the box.
"Now it's about gelling this team together. We had two new players this week and it will take time to play the football we really want to.
"Once that transfer window has closed we'll get a run of games and we'll know each other better."
Solskjaer gave debuts to Sean Morrison and Anthony Pilkington against Wigan, while Adam Le Fondre, Javi Guerra, Kagisho Dikgacoi, Guido Burgstaller and Tom Adeyemi have all joined this summer.
But the Norwegian hinted that the spending might not yet be over after a period in which the likes of Steven Caulker, Gary Medel, Jordon Mutch and Fraizer Campbell left the club.
"If some thing goes out you might have to bring someone in," Solskjaer said.
"If something spectacular or sensational comes up, as was the case with Pilkington, then we might have to go for it.
"But it's been a good week and a good start to the league.
"When football clubs start with winning games it creates a better atmosphere around the training pitches and the offices."
Wigan manager Uwe Rosler felt the Latics failed to get what they deserved and admitted he was still in the market for a new striker before the transfer window closes on September 1.
"I would have been devastated with a point," Rosler said.
"You think there will be more teams who dominate here like today? I don't think so.
"We were dominant for 90 minutes apart from putting the ball in the net.
"Cardiff were passive and I thought we were very good apart from the final third."
Rosler identified the lack of firepower as Wigan's main problem with the Latics having picked up only one point from three games.
"When you saw our last three games, and especially this one, everybody knows we have to do something on that part," he said.
"We have players who are very good, but I think we need more pace and more Championship experience up front.
"I know the market is more or less destroyed in the Championship and the Premier League but that is what we will try to get."