The Hornets went goal crazy after the break, scoring five and creating plenty of chances.
However, Zola has said that the scoreline was probably unfair because of the way Bournemouth played.
"Bournemouth probably didn't deserve to lose 6-1 because especially in the first half they played well and they played in the right way," he told BBC Sport.
"In the second half my team really put a good performance in and it was just what they needed because otherwise it was going to be difficult."
Zola said a change in "gears" was crucial to Watford's strong display.
He added: "We changed gears because in the first half we were playing under rhythm and we pushed a little bit higher up the pitch and that made it more difficult for them."
Watford lead the Championship table with maximum points from their two matches.