SANTIAGO (Reuters) - An independent leftist senator running for president in Chile’s 2017 election is leading in a head-to-head matchup against the right’s front-runner, a poll released on Wednesday showed, spicing up a race once expected to feature only establishment favorites.

Senator Alejandro Guillier is seen inside at the Chilean congress in Valparaiso, Chile September 27, 2016. Picture taken September 27. REUTERS/Rodrigo Garrido

The survey by pollster MORI shows Alejandro Guillier, a journalist turned politician, winning a potential runoff election by 5 points against Sebastian Pinera, a conservative, investor-friendly ex-president.

When asked who they would vote for in a race between the two, 35 percent of survey respondents said Guillier and 30 percent favored Pinera.

In a potential first round, the survey showed Guillier would take 19 percent while Pinera would take 23 percent, far short of the 50 percent needed to avoid a runoff.

Up until a few months ago, Guillier was a relative unknown in Chile, and most observers believed any runoff likely would be between Pinera and Ricardo Lagos, a moderate ex-president. However, far reaching political and corporate corruption scandals, as well as a sluggish economy, have fueled disenchantment will politics as usual in the South American nation, boosting outsiders.[nL1N1EF0PP][nL1N1E20RN]

The results of the most recent poll will be welcomed by left-leaning sectors of Chilean society, who believe profound reforms are necessary to soften the nation’s biting inequality. However, it complicates the outlook for investors who had previously seen the race as devoid of political risk.

“For Sebastian Pinera, vacation’s over,” said MORI director Marta Lagos. “Now he has a competitor and he has to go out and defend his position.”

In elections for mayors and councilmen in October, an anti-incumbent mood led to huge losses for the left-leaning Nueva Mayoria coalition, which held majorities at practically every level of government, in what was seen as a boost for Pinera.[nL1N1CU021]

But leftist independents unaffiliated with traditional parties also did historically well in many places, which could bode well for Guillier. A left-wing candidate affiliated with Chile’s student movement, for instance, won the mayor’s race in the country’s second largest city.

The MORI poll, which took place between December 7 and 15, included responses from 1,200 Chileans. It has a margin of error of 3 percent.