The Mexican rider, who finished second in the Giro d'Italia, soloed away on the Monte Serra with 27 kilometres to go and held off a small chasing group.
Michael Storer (Tudor Pro Cycling) won the sprint for second with Steff Cras (TotalEnergies) finishing third.
"“It was the team’s plan to try something today, but we knew it wouldn’t be easy. But my teammates did a great job from the start, and then in the finale I felt good and I tried the move that allowed me to win. I’m very happy," Del Toro told organisers at the finish.
"When I found myself alone in the lead, I just thought about pushing, and I knew I could do it. Tomorrow? Tomorrow at the Coppa Sabatini, we’ll see what happens."
A general view of Tyler Stites (Caja Rural - Seguros RGA), Nil Gimeno (Equipo Kern Pharma), Sam Brand (Novo Nordisk), Mattia Bais (Polti VisitMalta) and Adne Holter (Uno-X Mobility) in the breakaway (Image credit: Getty Images)
The 189.4-kilometre race around Pontedera went off in two phases: a drizzly first half with a five-man breakaway, and a drier closing section that included two trips over Monte Serra before a flat run-in to the finish.
The early breakaway came from Tyler Stites (Caja Rural-Seguros RGA), Ådne Holter (Uno-X Mobility), Sam Brand (Novo Nordisk), Nil Gimeno (Kern Pharma) and Mattia Bais (Polti-VisitMalta). They gained just over three minutes. Stites, Gimeno and Brand lost contact on the first ascent of the Monte Serra with 90km to go.
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The gap to the two remaining leaders was below a minute when Lorenzo Milesi (Movistar) bridged across but the breakaway was caught with 31km to go.
On the second ascent of the Monte Serra, the already much-reduced peloton shrunk further as Jan Christen (UAE Team Emirates-XRG) and Michael Storer (Tudor) attacked on the Monte SErra with 30.5km to go. They were joined by Paul Double (Jayco-AlUla) and Richard Carapaz (EF Education-EasyPost) but it was short-lived.
Once the remainder of the group rejoined, Storer attacked. Soon, Del Toro bridged across, chased again by Carapaz and Double.
Michael Storer of Tudor Pro Cycling leads the chase for second place (Image credit: Getty Images)
The four came together, but just before the summit, Del Toro attacked and left the other three behind. Carapaz chased alone at 15 seconds with Storer in a group at 40 seconds with 10km to go.
There was only one small unclassified climb between Del Toro and his 11th win of the season, and the Mexican only added to his advantage as the road tilted upward.
Laura Weislo is a Cyclingnews veteran of 20 years. Having joined in 2006, Laura extensively covered the Operacion Puerto doping scandal, the years-long conflict between the UCI and the Tour de France organisers ASO over the creation of the WorldTour, and the downfall of Lance Armstrong and his lifetime ban for doping. As Managing Editor, Laura coordinates coverage for North American events and global news.
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