Blackburn secured a scarcely deserved 1-0 win at home to struggling Sunderland but finally kept a clean sheet for the first time in 16 Premier League games.
Within four minutes Rovers had their opportunity from the spot after Samba's fierce shot hit Danny Higginbotham's arm. Benni McCarthy made no mistake with a powerful finish.
Sunderland's chance of salvaging a point were extinguished on 71 minutes when Rovers old boy Dwight Yorke was dismissed for two yellow card offences.
Blackburn have now halted three successive home defeats but boss Mark Hughes knows his team will need to improve their performances if a top six finish is to be achieved.
"Both penalties were correct decisions," admitted the Blackburn boss.
"Thankfully we converted our penalty and Sunderland didn't convert theirs.
"We've taken the three points in difficult conditions for both sides. In fairness to Sunderland they prevented us from playing our passing game in the first half.
"They probably feel aggrieved they didn't get something out of the game but sometimes, as we have found out, you don't always get what you deserve.
"Three games, seven points, we feel we are now back on track."