Finland's nationalist anti-immigration Finns Party suffered a heavy setback in this weekend's presidential election, as many of its anti-euro voters fled to the equally eurosceptic Centre Party, observers said Monday.

The Finns Party soared in popularity in last April's legislative elections, becoming the third-biggest political formation with 19 percent of votes as its vehemently anti-EU rhetoric drew voters away from the Centre Party, which struggled to convey its euro opposition.

But in Sunday's first round of presidential voting, the Finns Party candidate and leader, the charismatic and popular Timo Soini, managed to scrape up just 9.4 percent despite a campaign that focused heavily on Finland's role in the eurozone.

The Centre Party's candidate Paavo Vaeyrynen, representing the clean-cut, urban image of euroscepticism, meanwhile won 17.5 percent of the vote.

"Traditional supporters of the Centre Party defected to Soini during the parliamentary elections, but not permanently," Helsinki university political science professor Tuomo Martikainen told AFP.

The two big winners on Sunday, who will meet in a run-off on February 5, were in fact both pro-Europeans: Sauli Niinistoe, the conservative National Coalition favourite going into the poll, took 37 percent of votes while the Green League's Pekka Haavisto won 18.8 percent.

Analysts said Monday that the Finns Party's success in last year's legislatives was a protest vote against the then centre-led government, mired in campaign funding scandals and criticism over the appointment of top party positions.

The founders of today's Finns Party were originally members of the Centre Party, and both groups share a populist focus on issues important to the working class and the poor.

After losing his seat in the 2011 election, long-time eurosceptic Vaeyrynen returned to politics as the Centre's presidential candidate.

Campaigning on the same vociferous anti-euro platform as Soini, Vaeyrynen was able to win back supporters who defected to the Finns Party in April, researchers said.

"The Centre Party is now riding on Vaeyrynen's success," Turku university political scientist Ville Pernaa told AFP.

"They got back some supporters who went behind the Finns in April."

Soini insisted after Sunday's setback that he had not lost voter support.

"My supporters want me to stay on as party leader," he said.

Much of the election campaign focused on triple-A rated Finland helping to foot the bill for bailing out Greece and other fragile eurozone economies.

Media commented Monday that the outcome of the vote was a pro-euro triumph.

"The first round showed the position of the majority of Finns on the Europe question," an editorial in the Salon Seudun Sanomat, a regional daily, read.

Niinistoe, a 63-year-old career politician, was instrumental in leading Finland into the eurozone as finance minister from 1996-2003.

His opponent on February 5, the openly-gay Haavisto, is also pro-European and has strong green credentials forged as environment and development minister.

The president has traditionally played a key role in Finland's foreign policy, but in October parliament voted to hand EU policy to the cabinet with the prime minister now the main representative in EU affairs.

Despite that change, the euro issue dominated the campaign.

Finland's paper of reference Helsingin Sanomat meanwhile focused on the deep loss suffered by the Social Democrats, which for the first time in three decades will not hold the presidency after their candidate Paavo Lipponen won just 6.7 percent of votes.