Gentle gave Jake Birtwhistle a 40-second buffer over Alistair Brownlee that the individual silver medallist held to give their team, which also included Gillian Backhouse and Matt Hauser, the gold.
Each of the two male and two female competitors completed a 250-metre swim, seven-kilometre bike ride and 1,500-metre run in the race.
Hauser and Jonny Brownlee had been locked together at the halfway stage before Gentle put pressure on Learmonth to open up the gap they needed.
Australia finished in a combined time of one hour, 17 minutes and 36 seconds, with Alistair Brownlee crossing the line 52 seconds later. New Zealand clinched bronze in a time of 1:19.28.
“I can’t thank the Gold Coast and Australia enough for the amazing support, getting behind us all the way, is unbelievable”, Gentle said. “It was honestly the biggest relief when I saw Jake crossing the finish line. It was absolutely nerve-wracking watching the last leg, anything could have happened at the end there."
A performance worthy of gold 🥇 🇦🇺 Australia take the mixed team triathlon relay after @JakeBirtwhistle @AshleighGentle @GillianBackhous and @Matt_Hauser dominate the competition to cross the line first. #GC2018 #ShareTheDream pic.twitter.com/BCNQnHsyJN — 7CommGames (@7CommGames) April 7, 2018