The 43-year-old is currently ranked 179th in the Race to Dubai standings and faces an 11th trip to the European Tour qualifying school if he fails to break into the top 110 by the end of the week.
Hedblom fired a four-under par 68 to tie for the lead with Korea's Jin Jeong and Australians James Nitties and Clint Rice at Lake Karrinyup. The three-time European Tour winner needs a top-two finish to avoid a return trip to PGA Catalunya and knows he must keep up his form for the next three days.
"I'm so far back I need a win or to finish second really," said the Swede. "You have nothing to hold back; you just have to go for everything. You're not happy to finish third or fourth or fifth or sixth or 10th.
"The tension is nothing, really. Today it felt like any tournament - if I will be leading playing the last day, then maybe I'll feel the tension, but right now it's just one round out of four. It's good to at least have a chance to do it. The game is there, you just need a little bit of confidence."
England's Richard Bland, ranked 109th, shot a three-over-par round of 75 while Peter Lawrie - at one over - Oliver Fisher (par), Richard Finch (par) and Soren Hansen (one under) are the other players who need a win to avoid the qualifying school.
Jeong, the former amateur champion, who chipped in at the 18th for an eagle two, is another player who has made a good start. However, he knows there is still a long way to go. "It's only the first day and still three rounds to go and plenty of great players out here, so you never know what's going to happen," he said. "I've just got to do what I'm doing and just keep hitting good shots and hopefully that's good enough."
Further down the leaderboard, American Ryder Cup player Dustin Johnson opened with a three-under par 69 to be part of an eight-way tie for fifth.