Neil Warnock rued a losing return to the Championship as Cardiff were edged out 3-2 by Wigan.
The Bluebirds had beaten Manchester United at Old Trafford in their last outing in May before dropping back into the second tier.
They took the lead through Joe Ralls but Wigan recovered from the setback of a missed penalty by Josh Windass to lead through goals from Michael Jacobs and Windass.
Substitute Omar Bogle equalised with 20 minutes to go against his former side, only for Lee Evans to pop up with a stunning winner five minutes later.
All of which left Warnock, like the rest of the crowd, catching his breath – but disappointed with the outcome.
“It was nothing I wasn’t expecting, we know exactly how tough this league is,” he said.
“You have to take your chances and I thought we had chances to kill the game. We didn’t take them and poor defending at the other end has cost us dearly.
“They scored some cracking goals but they were poor defending from our point of view. They were preventable goals, and that’s something we have to learn from.
“I think one or two questions were answered today, if I’m honest, in my own mind.
“I’m so disappointed because I thought it was a game we could have got three points from, never mind one.”
Cardiff lost goalkeeper Neil Etheridge at the beginning of the second half but Warnock refused to use that as an excuse.
“It’s a hamstring problem and that’ll be a few weeks (out) I would think,” said the City boss. “But I don’t think that had too much bearing on the result.”
On the flip side, Wigan boss Paul Cook could not hide his delight at securing a third successive opening-day victory since taking charge in 2017.
“We’re delighted to start with a win,” he admitted.
“If you’d asked me at 10 past three last Saturday – when we’d just gone 2-0 down at home against Burnley in our last pre-season friendly, and we couldn’t even lift a leg – that we’d win an enthralling game like this first up, I’d have taken it.
“It was two teams who were genuinely trying to win a game of football. The game had everything and sometimes as a manager, you count yourselves fortunate when you come out the right side of a game like that.
“There were so many incidents, so many talking points, and to take all three points against such a very strong team is massive for us.
“Like every team we had a game plan, and we implemented it very well.
“But Cardiff are a very good team with very good players – and at any point they can change the dynamics of a game.
“Whenever you go a goal down, you’d be happy to take a point. To take all three points, you’re absolutely delighted.”