The G20 summit was drawing to a close after being overshadowed by Western anger towards Putin, with some of his fellow leaders raising the prospect of yet further sanctions against Russia.
The prime minister earned some love from Australian media for his dustup with the Russian president on the first day of the G20 meeting.
All-news networks and Australia's Sunday Mail reported on Harper's bold command to Putin at a private leaders' retreat ahead of the official opening of the summit earlier this weekend.
"Handshake came with a slapdown for Russian leader," read the headline of the Sunday Mail piece. It featured a photo of a beaver chomping on the Russian flag.
Australia's Business Insider also reported that Harper showed Australian Prime Minister Tony Abbott "how to shirtfront the Russian president." Shirtfront is an Australian expression for smack down.
Harper's spokesman, Jason MacDonald, said the prime minister was speaking to a group of G20 leaders at the retreat when Putin approached and extended his hand.
MacDonald said Harper told Putin: "I guess I'll shake your hand but I have only one thing to say to you: You need to get out of Ukraine."
A spokesman for the Russian delegation said Putin's response was: "That's impossible because we are not there."
Putin left the summit early, missing the official Day 2 lunch, following a meeting with British Prime Minister David Cameron and another strained encounter with French President François Hollande. The Kremlin said he had to get back to Russia for meetings.
In private talks that were reportedly "robust," Cameron warned Putin that Russia's entire post-Cold War relationship with the West is at risk due to the situation in Ukraine.
Hollande, meantime, has delayed a deal to supply two warships to Russia.
Australian Prime Minister Tony Abbott also lashed out at Putin for apparently flexing his military muscles by sending four Russian navy ships to stalk Australia's northern coast in the days leading up to the G20 summit.
Harper has been a vehement Putin critic for months, with Canada and Russia trading a number of retaliatory sanctions.
On the sidelines of the summit, one expert warned the Ukraine conflict could spark another world financial crisis due to the relentless back-and-forth economic sanctions between Russia and the West.
"You simply can't generate growth in Europe unless you get Russian troops out of Ukraine and get Russia to give back Crimea to Ukraine over the next five years," said Canadian John Kirton, co-director of the G20 Research Group.
"Unless Ukraine is solved the right way, you could get Russia canalizing or channelling a financial crisis."
On Day 2 of the summit, Harper met with top European Union leaders Jean-Claude Juncker and Herman Von Rompuy. He also sat down with Spanish President Mariano Rajoy Brey.
Harper also took part in G20 working sessions on global economic resilience. The G20 leaders are endorsing a plan to kickstart global economic growth and thwart corporate tax evaders.
Abbott, the chairman of the summit, released a set of strategies submitted by each member country aimed at increasing global GDP by 2.1 per cent in the years to come.
The measures will create millions of jobs worldwide, Abbott said Saturday.
The leaders are also expected to give the green light to measures that will strengthen global banking systems, safeguard the derivatives markets and address the dangers posed by banks considered too big to fail.
They're also slated to endorse an initiative to crack down on tax avoidance and tax evasion and ensure that company profits are taxed where they are generated.
On Day 1 of the summit, the leaders agreed to "extinguish" the Ebola outbreak, but they didn't pledge any new funding for those efforts despite pleas from health-care workers battling the outbreak for more resources.
Follow Lee-Anne Goodman on Twitter @leeanne25