STOCKHOLM, June 01, 2013 (AFP) - The 33-year-old continued his rich vein of form after finishing second in China and Morocco earlier this season with five birdies and an eagle to overtake overnight leader Matteo Manassero, who slumped to a one-under-par round of 71 and slipped to joint third alongside Swede Jonas Blixt and four shots off the pace.
Ilonen started confidently with a birdie on the second hole and followed it up with birdies on six and nine as he staked his claim for the lead in a bid to win his first tournament in six years and third on the European Tour.
"I need to shoot another low score and I can do it, but we've got 18 holes to go and lots of other guys are still hunting me," said Ilonen, who won both his tournaments in 2007 including a win in Stockholm.
Home hopeful Alexander Noren and 2011 champion is alone in second and two shots back after sinking a mammoth 80 foot putt on the fourth hole during a round that included seven birdies and an eagle.
Ilonen struck a superb approach to three feet at the 13th to set up a birdie, sank another from five feet at the 14th, and then saw a sand wedge spin back in at the 15th and drop for eagle.
"It was a bit of a funny yardage for me," he said of the eagle. "It was raining and I just tried to squeeze it in there and got lucky with it a bit," he said about a marvellous back nine.
Manassero, who became the youngest winner at the EPGA Championship last weekend at the age of 20 failed to take advantage of the favourable conditions and will begin Sunday's final round with plenty to do in a bid to make it back-to-back wins.
Austrian Bernd Wiesberger had a scintillating round of eight under par 64 to climb the leaderboard and now lies in a three-way tie for sixth with Dane Thomas Bjorn and Dutchman Joost Luiten while Rikard Karlberg of Sweden is one shot better off on 12 under par.
Englishman Paul Casey had a disaster with five bogeys and a double bogey to plummet down the scoreboard and signed a disappointing scorecard of 77 and three over for the tournament.
Third round leading scores from the Swedish Masters on Saturday:
198 - Mikko Ilonen (FIN) 70-63-65
200 - Alexander Noren (SWE) 67-69-64
202 - Jonas Blixt (SWE) Swe 70-66-66; Matteo Manassero 66-65-71
204 - Rikard Karlberg (SWE) 69-68-67
205 - Thomas Bjorn (DEN) 70-67-78; Joost Luiten (NED) 68-67-70; Bernd Wiesberger (AUT) 69-72-64
206 - Pablo Larrazabal (ESP) 66-70-70; Julien Quesne (FRA) 73-67-66