In the first half, Dirk Kuyt and Albert Riera had scored, before Gerrard took over with his set-piece onslaught.
The win means United's lead at the top of the Premier League is now one point - they also have a game in hand - but Liverpool have now scored more goals than Sir Alex Ferguson's men and have also established a slight advantage on goal-difference.
And Gerrard told Sky Sports 1: "The hat-trick means a lot but the points are more important.
"It (the scoreline) is more than what we expected, before the game we would have settled for a 1-0 win.
"Villa are a fantastic team who have been going really well - but they've had a dip in form of late and it was important we never let them settle.
"We got an early goal and built on it."
Gerrard acknowledged improving the Reds' goal difference was on his mind after Riera had made it 2-0 at Anfield.
He explained: "When you get a second goal, you start thinking of goal difference - but it's important not to get carried away.
"Manchester United are capable of winning their remaining games so it's just important to keep focusing on what we're doing. keep winning, stay on their shoulders and pounce on any mistakes they make.
"Chelsea are there too and we're still aware of them too."
The England midfielder acknowledged that confidence is high around Anfield at the moment, adding on Sky Sports News: "Every knows we are on a rich vein of form. Confidence is high here.
"It's a good break now. We go away with our international teams and hopefully will come back and get ready to go again."
However, he feared he may not get the chance for his first Premier League treble, adding: "Rafa likes to bring you off when you've got two to keep your feet on the ground."
Manager Rafael Benitez, said: "In the first half I thought we could be better.
"We have confidence but there are still a lot of games to play. We have to keep our feet on the ground and stay working hard."
It was the third stunning Liverpool victory in 12 days, having previous put four goals past Real Madrid and Manchester United.
The Spaniard added: "Physically teams are maybe a bit tired so they concede more.
"But my message is one game at a time and we will always try to improve."