It was a bold move by Pogačar, but one that paid off as he took the stage win and enough time on a dogged Wout van Aert (Jumbo-Visma) who valiantly tried to defend his race lead in the high mountains.
"Today was a very hard stage," Pogačar said. "My team did a great job bringing down the gap from the breakaway and then I did my best on the climb: I am very satisfied with this win."
"Now I am in the lead, but tomorrow we have another really hard stage, and with the final ITT anything can still happen."
While the gaps in the overall standings are still small enough that Van Aert's hopes of winning the general classification are not entirely gone, gaining 35 seconds back on Pogačar will be tough. Though given the remaining stages, including two hilly days and then a 10 kilometre time trial to finish, all of which suit van Aert down to the ground, the multi-discipline star might harbour ambitions of reclaiming the blue leader's jersey.
"It's a big gap," Van Aert said. "The next stages should be on me and I'm definitely not giving up yet. I think it makes particular sense to look up and seize the opportunities that arise. I'm going to keep trying anyway.
"Pogačar, together with my teammate Primož Roglič, is the best allrounder of the moment. It is only logical that he takes over my jersey."
The peloton got underway at the start of the day in picturesque conditions in Terni for the start of Stage 4 of the race between the two seas.
Mattia Bais (Androni Giocattoli-Sidermec) and Mads Würtz Schmidt (Israel Start-Up Nation) were the first to jump clear. Benjamin Thomas (Groupama-FDJ) and Emil Vinjebo (Team Qhubeka Assos) scrambled across, but soon Vinjebo lost touch and was chasing along with Marco Canola (Gazprom-RusVelo).
After about 35km of racing, the riders came together and forged out a sizeable lead over the peloton, with the gap ballooning from to nearly nine minutes after 48km as the peloton lacked momentum behind. The breakaway worked well together until the first classified ascent of the Passo delle Capannelle, where first Vinjebo and then Canola lost touch, leaving three riders to try and hold off the peloton, led by Bahrain Victorious working for Mikel Landa.
Würtz Schmidt attacked on the final climb to see himself the lone leader on the road, but in the peloton behind the attacks were beginning to fly as first Giulio Ciccone (Trek-Segafredo) went up the road. He was held in check by the peloton, but then attacks by Egan Bernal (INEOS Grenadiers) and two from Geraint Thomas (INEOS Grenadiers) saw the main bunch splinter dramatically.
Pogačar's surge began with 5.7 kilometres remaining, attacking to quickly catch and pass Thomas with 5.5km to go, then pass Würtz.
Van Aert was riding in pursuit to defend his overall lead, and he was strong to sweep up Thomas and drop riders of the calibre of Vincenzo Nibali (Trek-Segafredo) as they neared the summit.
With 4km to go, Bernal attacked van Aert and was followed by Landa and Simon Yates (Team BikeExchange), with Joao Almeida (Deceuninck-QuickStep), Nairo Quintana (Arkea-Samsic) and Sergio Higuita (EF Education-Nippo) chasing behind.
Yates attacked his group and set off in pursuit of Pogačar, who had an 11 second gap with 2.6km to go, while behind, Van Aert's steady tempo brought back all the other riders ahead.
Pogačar was able to hold off Yates, though he looked to be paying for his effort in the final kilometres as he crept over the finish line to win rather than flying over with his customary vigour. Yates finished just six seconds behind, with Higuita a further 23 seconds back in third as he crossed the line at the head of the splintered group of chasers.
Van Aert had nothing saved up for the dash to the line and finished in ninth, 45 seconds behind the new race leader, though the Belgian still sits second overall, 35 seconds behind Pogačar.