The Direct Energie rider comes from Diana Marina on the race route and described the Cipressa as "his gym, his office". He has ridden the climb and the descent hundreds of times in training, learning where he could gain time on the Milan-San Remo peloton.
He managed to open a 20-second lead by using his local knowledge and descending skills but on the coast road he was alone riding into a headwind and the peloton eventually swept him up on the lower slopes of the Poggio. He went on to finish 131st on the Via Roma, 6:31 down on winner Julian Alaphilippe.
"The team would have saved me for the Poggio but I felt empty at the start of the Cipressa and knew I wouldn't have stayed with the best, so I decided to go for it on the descent, I was hoping someone like Daniel Oss would come with me," Bonifazio explained to La Gazzetta dello Sport on Monday.
"I'd always dreamed about attacking on the descent of the Cipressa or Poggio at Milan-San Remo. It's 10km from my home, 20 minutes of warm-up and then I'm there. It's my gym, my office. I'm there every day. Well, it was, now I live on Monte Carlo."
Bonifazio went so fast that he caught a race motorbike and passed it. He tucked into an aero position on some sections of the descent and rarely touched the brakes as he descended at 85km/h.
"My friends said I did a 'Bonifazio'. My dad raced and he was a great descender before he quit racing and met my mum, I think I got it from him," Bonifazio explained.
"I love motorbikes and learnt how to ride one before a learnt to ride a bike, that's where I learnt my descending skills. I can't ride a motorbike now due to my contract but when I retire I'll be back on a cross country and road motorbike."
"I touched 85km/h on the straight sections and hardly touched the brakes, perhaps just two or three times. In races you don't really need brakes.
"On the descent I was looking ahead to the next corner, I was really concentrated but not afraid. I accelerated out of every corner to get back up to a high speed. I went for it but I didn't actually take a lot of risks. I know my limits and I'm good on descents because have to be; I often have to chase to get back on after climbs but that's rarely noticed."