Jason Smyth has won gold in the T13 100m at the World Para Athletics Championships in London, clocking a winning time of 10.63 seconds.
Smyth surged away from his rivals from halfway in a race confined to athletes with visual impairment.
The 30-year-old remains unbeaten in Paralympic competition since making his international debut at the European Championships in 2005.
Poland's Mateusz Michalski chased Smyth home in second, with Chad Perris of Australia third.
Speaking afterwards the five-time Paralympic champion said: "I knew from the heats I'd run the quickest and it was mine to lose, so it was just about going out and executing my race, being patient and thankfully I was able to cross the line first.'
"I had my wife and my daughter in the crowd, and all my family, and it's those moments that make it all the more special - to enjoy it with the people that mean the most."
Just minutes later, Michael McKillop won a second gold medal of the evening for Ireland and an eighth World Para gold of his illustrious career, taking the T38 800m in a season's best time of two minutes 0.93 seconds.
Australia's Deon Kenzie filled the runner-up berth and Tunisia's Abbes Saidi was third in the class for runners with cerebral palsy.
Speaking afterwards the four-time Paralympic champion said of the race itself: "Myself and my dad came up with tactics for today from Beijing 2008.
"No one in that race today was in my race in Beijing, so they didn't know what I was going to do. I looked over my right shoulder from 240m to go and did a pick up and the Canadian came right behind me and I just kicked and whenever I do that, no one can stay with me and I was able to come down the home straight knowing that I had a gap but I was able to keep driving on for the finish line."
Earlier in the day, Kildare man Patrick Monahan made his World Championship debut in the heats of the T54 1500m, finishing ninth in 3:14.65.
Three Irish athletes will take to the track on Monday.
Meath man Paul Keogan will feature in the morning session in the heats of the T37 200m.
Smyth races again in the heats of the T13 200m, with Dubliner Orla Comerford making her World Championship debut in the T13 100m afterwards.
Ireland scooped two silver medals yesterday in the discus. Orla Barry and Niamh McCarthy both finished second in their respective classes.