A controversial last-gasp penalty by Mikel Arteta handed Everton their first win of the season after Blackburn dramatically missed two spot-kicks.
Tim Howard was Everton's earlier hero when he saved a 46th-minute penalty from Blackburn's Junior Hoilett.
The giant American keeper then watched Mauro Formica's 77th-minute spot-kick slam against the post.
Arteta's late winner came after referee Lee Mason ruled Chris Samba had flattened Marouane Fellaini.
Despite a host of complaints from incensed Blackburn players, the penalty was awarded in the second minute of stoppage time and Arteta's confident finish condemned Steve Kean's men to their third successive league defeat.
Rovers had only themselves to blame, though. They had a chance of opening their Premier League account just after the restart after Everton's inexperienced Ross Barkley brought down Formica for a clear penalty.
Hoilett took careful aim but Howard gambled correctly, dived to his left, and kept the visitors in what was, until that point, a pretty mediocre game.
Blackburn, who dominated the game from a statistical point of view, got a second chance from the spot when Formica was brought down by Phil Jagielka.
But the otherwise impressive Formica could only watch in horror as his penalty hit the foot of the post and bounce away to safety.