Kwiatkowski escaped solo with just over 12 kilometres to race and navigated the final of the 11 white gravel sectors. He maintained enough to climb into Siena's famous Piazza del Campo with a 15-second margin over Greg Van Avermaet (BMC Racing).
The piazza roared to life with Kwiatkowski's arrival. He yelled too because he had bounced back from a difficult 2016. The timing was perfect, especially as Sky awaits a UKAD report and faces more parliamentary hearings.
"There are plenty of reasons," Kwiatkowski said of the troubles in his debut season with Team Sky. "I had health problems, but I was pushing my limits. I wanted to impress everyone in training and everywhere. I'm not like a machine, sooner or later you pay the bill.
"I had great support from the team, they always believed in me. I just had to wait and work hard to be back at that level."
The Pole won already in 2014 when raced with team Omega Pharma-Quick Step and through a season that eventually included a world championship road race win.
After 2015, he joined Sky. He was not his best throughout 2016. He won the E3 Harelbeke, but abandoned other races due to illnesses and back pains.
"I would've been just happy just to perform well today. I don't think a victory would've been necessary," he added. "I was already happy with the approach of the season that I had in Valenciana and Algarve, I felt that I was on a good level.
"I'm happy that I could win the race, but wasn't that it was all or nothing. I'm happy that it went like that because I had many difficulties last season, and I'm happy with the current situation."
He survived the rain and a massive pile up that caught many, including his Sky companions. He traded punches with cycling's top names: Van Avermaet, Zdenek Stybar (Quick Step Floors), Tom Dumoulin (Sunweb) and Tim Wellens (Lotto-Soudal).
"My sports director just told me the gap was growing, but he didn't give me one or two minutes, just always pushing me on the radio," Kwiatkowski said.
"That was perfect, I was motivated. It was necessarily not to celebrate the victory too early because everything can happen epically with this kind of weather."
This year, Strade Bianche is ranked in the WorldTour series. The victory gives Sky its first victory in the series for 2017, and it comes at a time when parliament and the UKAD are criticising the British team the hardest over TUEs and a mysterious package delivered to Bradley Wiggins.
Kwiatkowski preferred to talk about his victory. He would not respond when asked if the problems in England affected him and his season preparations directly.
"I don't know if they needed [the win]," he said of Sky, "but it's what I needed."
Thank you for reading 5 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try first month for just £1 / $1 / €1