With a 72-hole total of 280, the amiable Dane from Copenhagen finished at 15-under-par to collect her third professional victory on the Robe di Kappa Ladies European Tour.
She finished three shots clear of Swedens Linda Wessberg, who had a superb final-round 68 to finish at 12 under par.
Marine Monnet-Melocco from France, who was playing in the final group with Tinning, finished third on 11 under par, after firing a final-round level par 72.
Lynnette Brooky from New Zealand, who carded a 67, and Germanys Martina Eberl, who had a 72, shared fourth position on 10 under par.
Italys Sophie Sandolo was alone in sixth place on 9 under par and four players tied for seventh place, including third round leader Fany Schaeffer from France, as well as Nicole Stillig-Gogele from Germany, Asa Gottmo from Sweden and Rebecca Coakley from Ireland.
Tinnings victory moves her up to number one on the LET money list and third in the 2005 Solheim Cup standings, where there are seven spots for automatic qualification.
Patience was the key. I learned last year that you really have to be patient with golf before you get anywhere, said Tinning, who spent her 2004 season playing on the LPGA Tour in America.
You can be playing great and then you get a bad bounce and have a double bogey or something so you can never think that you have won after twelve holes or something because anything can happen in golf.'