McLachlan, who completed the course in 12hr 29min 40sec, said he was questioned in the days leading up to Saturday's race as to how he thought he would go against the new breed of young athletes coming through.
‘‘From my racing past, you have to race your own race, use your head and not just be pressured by them. So that's what I did.''
McLachlan's race was planned around his strength in the kayak, while words of inspiration from Nathan Fa'avae just before the start were an added bonus.
Fa'avae knew full well what McLachlan was about to embark on, as he had raced the event last year, finishing fourth in 12hr 12min 3sec.
The text message referred to McLachlan frothing at the mouth and being glazed in the eyes, and something about young buggers.
‘‘It served to make me just nail it,'' McLachlan said. He remembered the message from Fa'avae as he was running down the chute to the finish.
‘‘In case he was there, I had a bit of a milk drink I had packed in the thing and I was going to have it frothing out my mouth if I saw him. But I didn't see him.''
The gnarly 44-year-old veteran last contested the event as an individual 25 years ago, and he admitted afterwards to feeling a little lost at the beginning of the 33km alpine run stage.
‘‘I just thought that I'd have to follow someone that knows the way until I get to the top, anyway, and then leg it from there,'' he said of wanting to hold his position in the leading group coming off the cycle stage from Kumara, and being confident in his kayaking ability.
The tactics seemed to pay off in the run stage for McLachlan, in what in recent years has been the game-breaker in the event. He came through the transition point at the completion of the run at Klondyke Corner in seventh place, with Australian champion Jarad Kohlar and Andrew Sclater within sight.
Going on to the water, McLachlan made some big gains, moving past Brent Edwards, a past adventure racing champion, and Australian Alex Hunt around halfway to take over second place. He then worked on gaining a 10min buffer for the 70km bike ride to the finish.
But if there was any thought he might fade in the final section, it was quickly dispelled by the crowd along the way.‘‘I grew up Oxford way. There was a huge amount of support along the side of the road and that just kept me going.
‘‘I was hoping for top 10. But second is outstanding,'' McLachlan said of his podium finish.
He dedicated his result to his helpers behind the scenes, including Dougal Allen, who provided a training programme, and Braden Currie, who gave him race tips.
‘‘It all helped. But I'm too old for this,'' he added, referring to the event as his last fling and his wish to spend more time with his young family.