Henry, handed a rare start by Guardiola after being frozen out in recent weeks, scored the second goal from a free-kick with his first of 2010, and Rafael Marquez added a brilliant third with his first of the campaign from another set-piece 11 minutes before half-time.
Youngster Thiago Alcantara then added a fourth with his first career goal in the closing stages.
On Henry's goal, Barca coach Pep Guardiola said: "Let's hope it inspires him to score more and play even better.
"The team needs him much more now and I want more from him."
The Barca boss was happy with his side's performance but admitted they had won without having to work too hard.
"We won comfortably, without really shining," he said. "We did some things really well, but to compete at the highest level you have to give more and we need to demand more from ourselves.
"Without playing that well, we got a very favourable result - we defended really well, but we lacked rhythm when we had the ball."