The 22-year-old recorded the fourth-fastest time of the opening run and went down the hill for a second time chasing the time of Alex Vinatzer.
He beat the Italian by almost three tenths but still had a nervy wait with Zenhaeusern, Linus Strasser and Michael Matt all still to come.
Zagreb
WATCH: Noel's first run en route to Zagreb win
05/01/2020 AT 17:48
Matt had finished fifth in the slalom at Val d'Isere but missed a gate high up the course and failed to finish before Noel's last remaining threat, Switzerland's Zenhaeusern, took the slope.

WATCH: Noel's first run en route to Zagreb win

He led Noel at every checkpoint but with the margin narrowing rapidly and crossed the line agonisingly behind, pipped into second.
The Frenchman goes top of the slalom rankings courtesy of the victory, keen to go one better than last year when he was edged out by overall champion Marcel Hirscher.
The result also moves Noel, 11th in the overall rankings last year, back inside the top 20 for 2019/20.
Zagreb
WATCH: Noel's first run en route to Zagreb win
05/01/2020 AT 13:28
Zagreb
Storming second run from Shiffrin not enough for victory in Croatia
04/01/2020 AT 16:23