Hesjedal became the first Canadian to ever take the overall lead at the Giro d'Italia on Saturday.
Italy's Paolo Tiralongo won the seventh stage, while Victoria's Hesjedal came in at fifth place just behind Joaquim Rodriguez to take an overall lead of 15 seconds from Tiralongo.
"I didn't want to let this chance escape me and I have to thank all my team, especially (Christian) Vandevelde, for the incredible dream they are letting me experience," Hesjedal said. "I'm not here to win the Giro, my aim is to wear the pink jersey for as long as possible."
Hesjedal is competing in his third Giro, and is also auditioning for Canada's lone spot in the Olympic road race following the Tour de France.
Prior to Saturday, the closest a Canadian came to capturing the overall lead was in 1987 when Steve Bauer of St. Catharines, Ont., missed the pink jersey by 0.3 seconds.
"It's awesome, certainly a landmark accomplishment," said Bauer. "It shows the progress of our nation. Ryder is without a doubt a leader in the progress, on a large scale. ... It's long overdue, and great to see."
Tiralongo tussled with defending champion Michele Scarponi in the final 600 metres of the steep climb to the line before finishing the 202-kilometre leg from Recanati to Rocca di Cambio in five hours 51 minutes three seconds with a final sprint.
"I did a lot of work to get on Scarponi's wheels, then I thought I couldn't be so strong at the finish and so I continued at my own pace," Tiralongo said. "I waited until he sat back for a second and then I made an incredible effort at the finish. I ended completely out of breath."
Frank Schleck, one of the favourites to win the race, was three seconds behind Tiralongo in third. Two-time winner Ivan Basso finished eighth.
Christian Meier of Sussex, N.B., finished 99th to move to improve to 118th overall, and Dominique Rollin of Boucherville, Que., was 120th on the stage to go up 20 places at 150th overall. Svein Tuft of Langely, B.C., was well back at 174th for the stage, but managed to improve one spot to 161st.
Fumiyuki Beppu, Matteo Rabottini, Reto Hollenstein and Mirko Selvaggi broke away to build a gap of nine minutes on the peloton only five kilometres (three miles) into the stage. It was not until the climb up the category-3 Colle Galluccio that their lead started to be reduced.
Rabottini took off on his own in the final 30 km before being joined by Stefano Pirazzi 16.5 km from the finish. However, Pirazzi's chances of victory were dashed when he took a corner wide heading into the final section.
Jose Herrara led going into the final kilometre but was caught 700 metres from the line, seemingly setting up Scarponi for his first stage win of this year's race. But Tiralongo went around him in the final 100 metres for the Astana cyclist to cross first.
Gianni Meersman became the fifth rider to quit the Giro, after Pablo Lastras Garcia, Tyler Farrar, Thor Hushovd and Romain Feillu retired on Friday.
Stage 8 on Sunday is a 229-km leg from Sulmona to Lago Laceno with another uphill finish.