"It was incredible," smiled the Pramac Ducati rider. "I sincerely was hoping for the rain because yesterday went so bad and starting from P18 was so difficult."
The Italian was up to ninth by the end of the opening lap and soon challenging factory stars Dani Pedrosa and Jorge Lorenzo, which he admitted was a little daunting.
"At one moment I was behind Pedrosa and Lorenzo. I've never seen that situation. Only on the Playstation! So now what do I do? It's so difficult to pass them - especially because it's Lorenzo and Pedrosa.
"I was scared for Jorge after the race if I crash with him! I was scared about the reaction of Jorge, not the crashing. So I tried to keep some distance to him. But at the end everything went in a good situation."
At one stage the Pramac star closed to within 1.5s of race leader Valentino Rossi, putt ing him almost within reach of Ducati's first victory since 2010 and the first by any satellite rider since 2006.
"When I realised I was on the podium I was scared about crashing, because on the wet you never know your limit. But then Marquez crashed and - I don't know why - but Valentino was coming closer, closer and closer.
"I was scared I was too fast because it's not usual you gain that time to Valentino. It's not a comfortable situation.
"But usually when we are training with Valentino [at his ranch], when you are close to him he has something more. Last week we touched in one corner. I finished in front of him because I pushed him out. I thought, 'that's the last time we train together!'
"I didn't want to repeat that situation especially because I was happy for this great result. Coming closer to him was too risky and with two laps to go I saw I had created a little bit of gap to Dovi behind.
"In the last lap I think I made every corner wrong! Then in the last corner I started laughing and thinking 'now I wake up in bed'. So I'm very happy to be there.
"I'm happy also because we are three Italians. I am lucky because I am a friend of both of them. I go training with both. So I'm really happy for Valentino for the championship and especially for Dovi for the podium, again."
While Dovizioso has the latest GP15, Petrucci is riding last year's GP14.1.
"I was always fast in the wet, even with a not so competitive bike. I managed some 11th or 12th positions in the past. For everyone, for the media, it's not a good result but for us it was a good result.
"I came especially from motocross and maybe I have some advantage with the track changing every lap. Maybe I'm fast because in the wet everyone is slower! So in the box they told me 'we were scared about you, because you looked like you were crashing in every corner'.
"But for me as I say maybe everyone is slower and I don't understan d why. I really, really enjoy riding in the wet because everything is more smooth. It's more natural riding."
Petrucci is now up to eighth in the world championship. He is expected to get an upgrade to the GP14.2, as used by team-mate Yonny Hernandez, next time at Misano.
