The flight touched-down in Sydney about 12.30 p.m. after a marathon 19-and-a-half hour flight covering a distance 17,800 km from London carrying just 52 passengers and crew, reports news.com.au.
This was the second test flight in a three-part series for Qantas, which connected New York and Sydney in a non-stop trial flight last month.
It was also the second time in history the route has been flown by a commercial airline, with the first being in 1989.
The London-Sydney flight is actually 1500 km further than New York to Sydney, but is shorter due to prevailing tailwinds.
Ahead of the flight, Qantas CEO Alan Joyce explained that to make the non-stop journeys a reality within the next few years, the airline was looking at ways to redesign cabins and improve comfort to make the long stretches in the sky more manageable.
The project has been named Sunrise, after Qantas' "double sunrise" endurance flights during WWII which saw two sunrises while in the air.
Meanwhile, passengers boarded at 6 a.m. on Thursday (London time) and were offered high GI supper options like a steak sandwich or chicken broth with macaroni, followed by a milk-based pannacotta dessert.
Pilots wore an EEG device to track brain wave patterns, while three Go-Pro cameras were put in the cockpit to monitor alertness.
A final decision on whether the ultra-long haul flights will become a commercial reality is expected by the end of the year, with the service potentially launching by 2022.
Ahead of the flight, Qantas CEO Alan Joyce explained that to make the non-stop journeys a reality within the next few years, the airline is looking at ways to redesign cabins and improve comfort to make the long stretches in the sky more manageable.
( With inputs from IANS )