Argentina-born Pizzi's countryman Pablo Piatti drilled home the opener just before half-time and the influential Sofiane Feghouli sealed the win midway through the second half with a neat finish.
The result gives Valencia only their third victory in 11 Primera Division matches and ensured new boss Pizzi of a happy debut after being confirmed as the permanent replacement for Miroslav Djukic on Boxing Day.
The 45-year-old Pizzi, a former Spain international who played for the likes of Valencia, Barcelona, Villarreal and Tenerife in his adopted country, would have been desperate for a good start after taking over a side languishing in 11th place in the standings and only five points above the relegation zone.
However, his side had a scare in the opening minute when they survived a Levante penalty appeal, Pedro Lopez crashing to the ground after nicking the ball away from Juan Bernat as he was attempting to clear from inside the area.
Play was waved on though and Valencia started to take control before coming within inches of taking a 37th-minute lead when Feghouli sweetly-struck half-volley from outside the box fizzed just wide of the far top corner.
Levante were not so fortunate five minutes later though as Valencia did go ahead.
Loukas Vyntra's defensive header from a Bernat cross only went as far as Piatti inside the area and he took the ball down on his chest before smashing a left-footed strike past Keylor Navas and into the far corner.
The home side continued to look the more dangerous in the second half and Jonas, Feghouli and Helder Postiga all tried their luck before Levante gave home goalkeeper Diego Alves something to think about with efforts from David Barral and Simao.
Simao can feel slightly unfortunate that his well-struck 30-yard effort went straight at Alves as it could have caused problems had it been a yard or two either side, but that was the closest Levante would come to an equaliser.
Immediately after that chance Valencia raced down the other end and Feghouli curled a left-footed effort just wide, and two minutes after that Los Che got the decisive second goal.
It was that man Feghouli again as the Algeria international picked the ball up and raced into the area, where he stepped outside Issam El Adoua before neatly dinking his shot over Navas and in off the underside of the bar.