Charlton boss Lee Bowyer believes the 2-1 victory over Blackburn at Ewood Park proves that his team belong at Sky Bet Championship level.
The Addicks enjoyed the perfect start to life back in the Championship following their play-off victory last season.
Ben Purrington's close range half-volley gave the visitors a lead against the run of play before parity was restored nine minutes after the restart through a freak own goal by Dillon Phillips.
But Charlton would not be denied, as Lyle Taylor's neat flick 13 minutes from time sent the visiting support into raptures and they professionally held on to take the three points.
Afterwards, Bowyer said beating a side that finished mid-table last season showed his team will be competitive this time out.
"I said 'go out there today and give me everything and prove to everyone that this is where you should be'," he said.
"A lot of people are doubting us and obviously we're favourites to go down but with the group I have, they just keep fighting and battling, and we have quality as well.
"We didn't play as well as we can in possession, we gave it away more than normal. Defensively we were solid. Tactically, we got it right.
"OK, they had possession, but they're the home side and they're a good side. They've got players that can hurt you and we had to respect that.
"The togetherness and fight, they just don't give in. They always believe they're going to win, because we've drummed it into them.
"There'll be times we lose at home and away but it won't be through lack of effort."
Rovers have now gone nine years since winning on the opening day, and defeat was their first after three undefeated at the back end of last season at Ewood.
Tony Mowbray was left to rue his side's inability to unlock Charlton's resolute defence.
He said: "We're left frustrated. I thought there was a lot of good stuff today. A lot of domination of the game but ultimately the frustration was the quality in the box, the final pass, the clinical side of the game to create and score chances.
"There's the frustration. Our Achilles heel from last year was there again I suppose.
"It was difficult to get through but nobody says you can't come and defend and make life difficult for the home team.
"That's why I said better quality in their half of the pitch, a better-quality pass, better finishing. Just a frustrating day. They didn't have to work too hard, particularly the second goal.
"They managed the game out pretty well, slowed it down, and here we are frustrated, opening-day defeat and we move onto the next one.
"We sit here with a defeat because of our inability to defend a corner. At 1-1, there was only going to be one winner.
"A football team is a football team and everybody has to work hard in possession and out of possession, and today suggests we lost because of our inability to put the right ball in the box, with the right quality at the right time, just as (much as) our inability to defend our own box."