City lost ground after a United defeat in the Manchester derby over three weeks ago, and since suffered a shock Boxing Day loss to Sunderland.
Right-back Zabaleta feels his City side have responded well to setbacks but they must keep working if they are to be in contention for the title.
He said: "The most important thing is always the performance of the team.
"We played a great game, we had a lot of chances, defensively we were very solid and it's another clean sheet.
"It's a good three points to carry on and we know that we are under pressure because we need to win every game.
"We know we are seven points behind United so it's going to be very tough, but keeping positive and keeping working is the key to catching United.
"It was hard to lose against Sunderland but always you need to try to respond well. We did it and I'm very proud for the team."
The 27-year-old scored City's opener in their 3-0 win over stoke on New Year's Day, a performance that again underlined his value to the champions.
He said: "You feel great when people give you credit but I always try to put the team before me.
"Football is not about individual players, it's about the collective. I'm very pleased for the lads.
"We did great yesterday and it's great when you see everyone play well."