The 34-year-old became the first to pull off the double when he won the Grand Prix Cycliste de Montreal in a sprint finish on Sunday, two days after taking an event in Quebec City.
With his 2012 win in Quebec City, Gerrans is also the first to win three times since the two races joined the UCI WorldTour five years ago.
"These races suit me really well," the leader of the Orica GreenEdge team said. "Difficult circuit races, with quite a lot of climbing, and you have to be explosive to be in the front.
"Traditionally, I'm in good shape at this time of year, so it's a combination of all those things. I really enjoy coming to Canada."
The 17 laps of a 12.1 kilometre course up and down Mount Royal in the centre of the city came down to a 21-man sprint. Gerrans finished clearly in the lead ahead of Rui Costa, the reigning world road race champion from Portugal, and Frenchman Tony Gallopin of the Lotto Belisol team.
Mike Woods, spurred on by a large cheering section from his home town of Ottawa, was top Canadian in 26th place.
The victories showed that Gerrans is in peak form headed into the world championship road race Sept. 28 in Spain, where perhaps another showdown with Costa awaits.
"It's a hard course and I think you'll see guys with legs in front in the final (part of the race)," said Gerrans. "By winning the two races here in Canada, I've shown that my form's right on track and I hope to be a real contender."
Costa, a winner in Montreal in 2011, was quite happy to burden Gerrans with the "favourite" label heading into Spain.
"I don't know the world championship course very well, but colleagues told me a lot about its characteristics and that Simon could be one of the key riders, maybe the No. 1 favourite," the Lampre-Merida team leader said with a big smile at Gerrans.
Gerrans picked up 80 points toward UCI road race standings. His 478 points are third in the world, but he actually lost ground to leader Alberto Contador, who won the Spanish Vuelta on Sunday to move to 620 points.
The Aussie will likely be pleased to hear that race organizers announced that the Montreal and Quebec City races will be extended for at least another five years.
Gerrans credited his teammates with perfect race management, both to keep tabs on a long four-man breakaway that started on the first lap and for having five riders in position to help finish it off.
The early breakaway group included the Canadian national team's Ryan Roth of Kitchener, Ont., Jan Polanc of Lampre-Merida, Arnold Jeannesson of FDT and Louis Vervaeke of Lotto Belisol. They built a lead that eventually reached more than 11 minutes ahead of the peloton.
Led by the Astana team, the pack reeled Roth and Jeannesson in with three laps to go. Vervaeke was caught with a lap and a half to go, but it took until the last lap, about 10 kilometres from the end, to catch the 22-year-old Polanc.
The Slovenian rider had also been part of an early escape in Quebec City.
With the breakaway neutralized, Costa attacked twice on the last lap, but was caught both times.
"My aim was to avoid a large group on the final straight because the sprint would be complicated, so we tried to make the race as demanding as possible," said Costa. "I tried to push on the final hill, but in the sprint, Gerrans was faster than me. But I think it's a good result."
Describing the final sprint, Gallopin said: "The legs spoke and Simon was much too strong. The battle was for second place."
The field of 151 riders included 18 of the world's top teams plus a eight riders from the Canadian national squad, including Roth and Woods.
Their leader, Ryan Anderson of Edmonton, was top Canadian in Quebec City in 27th place.
"It was a difficult day," said Woods, who finished in a group seven seconds behind the lead sprint. "As a national team, you don't get a lot of respect from the other teams, so we had to battle to get to the front.
"We weren't expected to do much, but both races we did things. It was a big success for the national program."
A nagging knee injury forced Europcar rider Antoine Duchesne of Saguenay, Que., to retire halfway through.
The five hour 24 minute 27 second race went 205.7 kilometres, with 229 metres of climbing per lap.