The Hornets are unbeaten in their last four matches following their 2-0 win over Ipswich Town at Portman Road.
"We're really playing well away from home. I'm delighted and I have to admit to being surprised by what these players are doing," Zola said.
"They're really performing to levels that are unexpected by me, considering that we're a young team that have just been assembled this year."
Watford are just three points behind Hull City in the automatic promotion places as they lie in third place in the Championship.