[2] Hjertstedt turned professional in 1990 and joined the PGA Tour of Australasia, where he tied for 7th at the New Zealand Open and for 4th at the Australian Masters at Huntingdale Golf Club.

In 1992, he played on the Japan Golf Tour, where he tied for 16th at the Pepsi Ube Kosan Open and 17th at the Acom International.

Open in New York the same week that Europe won that year's Ryder Cup at Valderrama Golf Club, to become the first Swede to win on the PGA Tour.

[4] He followed up in 1999 by claiming his second PGA Tour title at the Touchstone Energy Tucson Open after he birdied the first hole in a playoff with Tommy Armour III.

[5] He represented Sweden in the Dunhill Cup in 1994 and again in 1999, where he tied for 3rd together with Jarmo Sandelin and Patrik Sjöland, after he lost to Australia's Craig Parry on the first playoff hole in the semi-final.