He broke away from his main rivals with around 78 km to go of the 201 km race, which starts and finishes in the city of Siena in the heart of Tuscany.
At first, only 19-year old Seixas was able to follow Pogačar's wheel. He was joined by Pogačar's UAE Team Emirates XRG teammate del Toro.
The young Frenchman, who rides for the Decathlon team, is being tipped as a future star of the sport and a potential winner of the race in years to come.
Afterwards, Pogačar paid tribute to his team, saying, "probably I always say this but chapeau (hats off) to the teammates today. Everybody did an incredible job. It was just beautiful to see all the guys in the team performing so well. It was an honour to ride with such a team today and to deliver the win and so I'm super happy."
The next race on Pogačar's itinerary is the first of cycling's Spring Classics, Milan-San Remo, on 21st March.
