Shane Duffy had a night to forget in Cardiff as he scored two more own-goals before being sent off in a 2-1 loss that continued Blackburn's wretched start under Owen Coyle.
The Derry born Republic of Ireland international found the net at the wrong end at Wigan on Saturday and his luckless season continued with a pair of own goals inside the opening 20 minutes.
Duffy, who this week rejected a new contract with Rovers, saw the ball ricochet off him after Declan John's shot hit the post and he doubled the Bluebirds' advantage by directing Peter Whittingham's free-kick beyond Jason Steele.
Blackburn's winless start in the league extended to three games despite Danny Graham reducing the arrears late on and Duffy's dire evening was rounded off with a second caution in stoppage time for kicking the ball away.
Championship favourites Newcastle got their first points of the season with a 4-1 win over Reading in front of 48,000 at St James' Park.
Summer signings Isaac Hayden, Matt Ritchie and Dwight Gayle all scored for Rafael Benitez's side, who had lost both of their opening two fixtures.
The only 100 per cent record in the division was ended after QPR lost 3-2 at Barnsley.
A win would have sent Jimmy Floyd Hasselbaink's side to the top of the table.