Marc Leishman is firmly in contention to win The Open, just months after his wife's battle with a serious illness left his golfing future in doubt.

The Australian shot an eight-under 64 in his third round at St Andrews on Sunday to move to tied second on nine under, one stroke behind leader Dustin Johnson.

The 31-year-old's wife Audrey was placed into a medically-induced coma after being admitted to hospital with toxic shock and acute respiratory distress syndrome in late March.

Leishman abandoned his preparations for The Masters to care for Audrey – who was given a five per cent chance of survival – and was faced with the possibility of giving up the sport to look after their two children.

But, after her remarkable recovery, Leishman returned to the tour and has the chance to win his first major of his career.

"It's [his wife's illness] changed my whole perspective on life. I feel like I've always had a pretty good outlook on life, but now just it takes a lot more to worry me," Leishman said. 

"It was a huge possibility that I wasn't going to be playing golf anymore. Travelling with a one-year-old and a three-year-old by yourself isn't really - well, it wasn't going to happen. I wouldn't do that to the boys. 

"It's great that she's healthy again. But yeah, that was pretty rough there for a while, thinking about everything, the boys not growing up with their mom, me not playing golf anymore, not having a wife.

"She's getting stronger, and it's just going to take time. Might take a year, might take two years, who knows, but she's here to tell the story.

"It would be great to get a hold of that trophy and nice to take it back for Audrey and the boys. I'm sure it would be, yeah, a pretty big party.

"There's no doubt about that. But if I don't, I'll be all right. Obviously your life is a lot better if you do and you're successful and all that, but I'm doing what I love, and I've still got my family."