STOCKHOLM, June 02, 2013 (AFP) - The 33-year-old Ilonen, the overnight leader who had finished second in China and Morocco earlier this season, hit a final round, three-under-par 69 to bag a 21-under total.
That was three shots ahead of Sweden's Jonas Blixt, with Austria's Bernd Wiesberger sneaking third on 17 under.
Ilonen's two previous victories on the European Tour came in 2007 - the latter in this event.
The Finn had carded rounds of 70, 63 and 65 heading into the final day and continued to make his mark, sinking birdies on the second, third, 11th and 13th holes, his only error a bogey sixth on the long 12th.
"It's pretty special," said Ilonen. "I could feel a lot of support from Finland, especially today."
He downplayed his bogey on the 12th, saying: "I just got ahead of myself with the first putt.
"I've said for weeks now it doesn't really bother me if I make a bogey because I know I can make it up and it was the first time I went for the 13th in two."
Collated leading final scores from the Swedish Masters on Sunday at Bro Hof Slott GC, Stockholm(GBR and IRL unless stated, par 72):
267 - Mikko Ilonen (FIN) 70 63 65 69
270 - Jonas Blixt (SWE) 70 66 66 68
271 - Bernd Wiesberger (AUT) 69 72 64 66
272 - Alexander Noren (SWE) 67 69 64 72, Thomas Bjorn (DEN) 70 67 68 67, Matteo Manassero (ITA) 66 65 71 70, Rikard Karlberg (SWE) 69 68 67 68
273 - Ross Fisher 72 67 70 64
274 - Felipe Aguilar (CHI) 71 67 70 66, Julien Quesne (FRA) 73 67 66 68
275 - Henrik Norlander (SWE) 73 67 67 68, Joost Luiten (NED) 68 67 70 70, Jamie Donaldson 67 70 72 66
276 - Soren Kjeldsen (DED) 70 69 69 68, Damien McGrane 73 67 68 68, Peter
Whiteford 71 63 73 69, Miguel Angel Jimenez (ESP) 72 67 68 69, Pablo Larrazabal (ESP) 66 70 70 70, Gregory Havret (FRA) 69 70 70 67
277 - Emiliano Grillo (ARG) 69 71 70 67
278 - Francesco Molinari (ITA) 70 67 73 68, Jose-Maria Olazabal (ESP) 72 68 71 67, Peter Uihlein (USA) 71 70 68 69, Richard S Johnson (SWE) 72 66 71 69, Paul Lawrie 70 71 68 69, Rhys Davies 69 70 68 71
279 - David Drysdale 71 68 71 69, Maximilian Kieffer (GER) 71 69 69 70, Alejandro Canizares (ESP) 68 72 70 69