Kreutz, who began the day two shots behind the overnight leader, Samantha Head, from England, made a fast charge on the back nine to finish four shots clear at 14 under par (199) for the tournament. She tacked a closing round of 66 (-5) onto opening rounds of 69, 64 for a runaway win.
Minea Blomqvist, the defending champion from Finland finished tied in second position with English players Samantha Head and Lora Fairclough at 10-under-par 203.
While Becky Brewerton, from Wales, Marta Prieto, from Spain, and Nina Reis from Sweden tied for third position at 9-under par (204) on a sweltering final day at Old Lake Golf G&CC, near Budapest.
Kreutz started out slowly but began her birdie blitz from the par-5 fourth hole. She then birdied the sixth and eighth, to tie for the lead with Head. The turning point came when Kreutz birdied the ninth to move to 13 under, while Head made a double to take her back to minus-10.
Two more birdies at the 10th and 17th gave the French woman a five shot lead coming down the last, but despite finding the greenside bunker at the 18th, a bogey was enough to seal the win.
After the first nine holes, I had a two shot lead, so I felt more confident, admitted Kreutz, 31, from Rognac.
When I made my first birdie I just tried to get on a roll.
When she claimed her second professional victory at the Tenerife Ladies Open in May, Kreutz achieved her goal to achieve automatic exemption for the Evian Masters, which takes place next week in France.
Im very excited about Evian and the British, to see all those champions, but Im going to try not to be too stressed and relax, because next to some of them I feel like a little girl! she said.
Kreutz collected her maiden win on Tour at the 2003 La Perla Italian Open after five years as a professional.
This win takes her to third in the money list and fifth in the automatic Solheim Cup points rankings, where there are seven automatic qualifying spots available in the European team.
Earlier in the day Englands Rebecca Hudson set the pace by carding a course record equalling 62 (-9).
Hudson, 26, from Doncaster in England, started her birdie campaign at the second hole, with a simple tap in. She then birdied the fifth and eighth holes to turn in 32.
Then, she went birdie, eagle, birdie, eagle, from the 12th hole, taking full advantage of the par-5s. At the 13th, she chipped in for eagle and at the 15th, she holed her sandwedge from a full 73 yards.
Another birdie at the 17th put her on course for a possible course record as she was 10 under coming down the 18th. However nerves got the better of her and she three putted the last for bogey to come home in 30, equalling the course record set in the first round last year by Finlands Blomqvist, the defending champion.
I only needed a par to break the course record as I was ten under coming down the last, said Hudson.
But I must be getting older, as Im feeling my nerves these days! Its been a while since Ive shot those sorts of scores.
Hudsons 62 is her best round as a professional, but she actually carded a 10-under par 62 as a 16-year old amateur in a club competition at Wheatley GC.
Ive been having a tough time recently but Ive been working a lot on my swing and my putting and so this result should be enough to see me keep my card. Now I can just relax and play my game, she said.
Katherina Werdinig from Austria was the top finishing amateur, finishing at one under par for the tournament.