Northern Ireland runners Jason Smyth and Michael McKillop won gold medals at the Paralympics on Saturday night.
Smyth, 25, from Eglinton retained his 100 metres T13 title, bursting away from the field to win in a world record time of 10.46 seconds.
Glengormley man McKillop, also a hot favourite to repeat his Beijing win, was a runaway winner of the T32 title over 800 metres.
McKillop also set a new world best, coming home in 1.57.22.
Australian Brad Scott was with McKillop at the bell, but the Irish man went it alone for the final 400 metres and the 22-year-old finished more than four seconds ahead of Tunisia's Mohamed Charmi with Scott taking bronze.
McKillop said watching Smyth's victory earlier had inspired him.
"We are best friends and room-mates. I could not have walked into that bedroom tonight without a gold medal around my neck," said McKillop"
Both athletes can each win a second gold later in the Games.
Michael McKillop was the runaway winner of the T32 800 metres
Sprinter Smyth, who won double gold in 2008, is targeting another success in the 200 metres while McKillop goes in the 1500m final on Monday.
McKillop is unbeaten at Paralympic level for six years and won over his two distances at last year's World Championships.
Smyth, visually impaired because of Stargardt disease, was disappointed not to qualify for the Olympics, missing the 100m 'A' standard by 0.04 seconds.
The fastest Paralympian in the world spread his arms wide in celebration as he crossed the line, winning by a margin not even Usain Bolt is accustomed to.
The reigning champion's victory was never in doubt as he won by over half a second from Cuban Luis Felipe Gutierrez.
Smyth has run quicker, but only in non-disabled competition.
Another Paralympic crown helped make up for the Derry athlete's disappointment at missing out on Olympic qualification.
Draped in an Irish flag which declared him the 'fastest Paralympian on the planet', he said: "Coming in as champion, you are under pressure to retain your titles so thankfully I was able to do that.
"It was an added bonus to run quickly and break the world record again.
"To be in that stadium with 80,000 people, half of them seeming like they're Irish cheering, and even the British were really supportive, makes the whole Games a lot better."
Asked if it made up for his Olympic absence, he said: "It was very disappointing to be so close, I had put in a lot of hard work to try and get there and it would have been fantastic.
"There is definitely something sweeter about coming to a major event, succeeding and coming away with the gold medal."
Earlier, Ireland celebrated gold in the pool when Darragh McDonald won the 400m freestyle S6 in a time of 4.55.56