"This will have sent a message out to United and Chelsea. Let's not kid ourselves, they'd have been watching the game," said the vice-captain.
"When you play Real Madrid and Manchester United and score so many goals, you know in the back of your mind that can't happen every week so to get five against Villa was a magnificent achievement.
"If we'd have dropped points against Villa, United's defeat at Fulham wouldn't have made that much of a difference but we've capitalised on it.
"Now United will realise they are in a fight for the league."