The two races were held side by side here over the same 750 metres swim, 20 kilometres hand-cycle and 5km wheelchair racing distance as seen in the swim-bike-run competitions earlier this week.

Extra intrigue was provided by the combining of the PT1 and PT2 classification classes, with those in the former and more serious impairment beginning with a three-minute head-start.

Townsend, among those starting from further behind, was languishing behind Australia's five-time world champion Bill Chaffey after the swim as another home athlete, Nic Beveridge, powered ahead from the leading group. 

Pre-race favourite Chaffey began to close the gap to his fellow countryman on the hand-cycle but then disaster struck as he crashed into a fence and, after a delay, battled gamely on without a handle.

Townsend soon powered past and then overtook Beveridge - albeit after the two nearly collided - at the end of the cycle segment before pushing further ahead in the wheelchair finale. 

He slowed to celebrate as he crossed the line in 1 hour 02min 39sec.

"Swimming has always been a downside of mine, I'm one of the weakest swimmers in the field, it's something I have worked greatly on over the winter and I knew if I could keep the gap I wouldn't get passed from the back," Townsend said.

"I found myself in the lead coming out of T2 [transition two] and I knew others in the field couldn't push past me, it seems narrow minded but I know what my strengths are and it was a dream finish for me."

Townsend is a former Royal Marine Commando who lost both legs in an explosion in Afghanistan in 2008. 

He carried the Paralympic Flame into the Olympic Stadium at London 2012 as part of the Opening Ceremony in which he made a dramatic overhead entrance suspended by wires - despite being scared of heights.

Beveridge crossed second, 49 seconds behind as Chaffey held-on for third another 45 seconds adrift.

The women's race was following a similar pattern as Jones also powered through the field.

Jones is a wheelchair racer by trade and won a 1500m T54 bronze medal at Glasgow 2014.

The 22-year-old proved fastest in all three components as she crossed the line in 1:11:07, 1:49 clear of her nearest rival.

"I was always chasing which is tough mentally, but to push through was great," Jones, who is also competing in athletics events here, said. 

"I swam really well and I have been working on my swimming for the past six months. 

"Anybody who knows me knows how much this means to me.

"I have only been doing Paratriathlon for 18 months, and although I have made a lot of improvements, I still have a long way to go."

Reigning world champion Emily Tapp overhauled fellow Australian Lauren Parker late-on to take the silver medal.

Parker, who started from the last group and only took up Paratriathlon 12 months ago after a freak training crash ended her Ironman career and left her confined to a wheelchair, then collided with the railings on the final corner and was left prostrate on the ground.

She was helped back to her chair before composing herself for the final 100m to take bronze in 1:13:48.