He was taken to a fifth extra hole by Henrik Stenson, as the Swede recorded his best finish since the extraordinary 2013 campaign in which he topped money lists on both sides of the Atlantic.
Spain’s Rafael Cabrera-Bello and Frenchman Gregory Havret also fell away in the play-off, having finished alongside Zanotti and Stenson on 19 under par. England’s Simon Dyson and Welshman Jamie Donaldson were one shot further adrift.
Zanotti carded a bogey-free final round of 65 and sustained that record through a marathon play-off, world No2 Stenson conceding at the fifth extra hole after finding water and then a bunker.
“I was patient. I tried to play shot by shot in the play-off. I’m just very happy,” said the 31-year-old, who is set to be among the biggest climbers when new world rankings are published today.
“I knew if I made a good run I’d have a good chance. It was my day. I’ve been working a lot and trying to build my confidence to get to this moment and finally I’m here.”
Stenson missed a putt at the 18th to win his first title since November and wasted a similar opportunity at the first extra hole. Cabrera-Bello finished his round with a birdie-eagle sequence but found the water at the fourth extra hole.