Highlights of Dean Mercer's 2005 Coolangatta Gold tilt inspired Day the day of the late ironman's death.

So it was no surprise on Sunday when Day channelled Mercer's ruthless approach to racing as he equalled Caine Eckstein's record with a fifth win.

Day was pushed early by Shannon Eckstein in the short-distance expert's return after a 10-year absence from the 41.8km epic.

But Day chased him down after the ski leg and took a decisive 1min 40sec advantage into the board leg.

It meant he could savour the experience on the final 7km beach run in what were perfect racing conditions on the Gold Coast.

Day, like all competitors, wore a wrist band that said 'Doing it for Dean' and a minute's silence was held before the race that reduced surf lifesaving great Trevor Hendy to tears as he embraced Dean's brother Darren.

"He's been a massive inspiration for me and that one today was for him and his family," Day said of Mercer, who suffered a heart attack and died in August.

"The day Deano passed away, I was about to head off to training and I YouTubed a Dean Mercer highlight reel from Coolangatta Gold '05 and at the best of times it brings tears to my eyes.

"Those times you didn't want to go to the gym or jump in the pool; they're not hard, but those little moments you draw on and get emotional and those feelings make it so worth it."

It was Eckstein's first race since double calf surgery to stop cramps and pain when running long distances.

Admitting the result went as expected, Eckstein said Day's effort reminded him of the man they were all racing for. “He's not the prettiest ironman to watch," Eckstein said of Day. “But he keeps going and going and going like Deano and that's what it takes to win those endurance races.”

Meanwhile Allie Britton came from a long way back to push Courtney Hancock, who held on for her third crown. Britton had the second-best run leg of the day – quicker even than Day's – to come within 200m of Hancock on the finish line. AAP