The 17 year old had already lifted 400m Freestyle silver and 100m Backstroke bronze but rose to the top spot of the podium with a dominant performance in his main event.
Having qualified second fastest, the European champion looked the man to beat throughout, turning second after 100m before taking over in the breaststroke leg.
And after beating his own European record to finish a body length clear in two minutes 24.63 seconds, Hynd admitted he couldn’t have hoped for a better final.
“That went really well. It was everything I dreamed it could be so I’m really happy,” said Hynd.
“I’ve worked a lot on my breaststroke so I’m really pleased I was able to hold my own on that stroke.
“The noise gave me a hint that I’d won but I wanted to see it to believe it so I turned and saw the one next to my name and that’s when I knew I’d done it.”
Oliver’s brother Sam Hynd was also in action in the SM8 200m Individual Medley, defending his bronze medal from the 2008 Paralympics.
Sam set a season’s best 2:28.03, but he was always playing catch-up in the second 100m and couldn’t quite reel in the Netherland’s bronze medallist Maurice Deelen (2:27.17).
Louise Watkin equalled her British record in the S9 50m Freestyle as she scored silver in her first individual event of the Games.
The four-time Paralympic medallist from Beijing had qualified fastest for the final and touched in 29.21 seconds for her medal behind China’s Lin Ping (29.12).
“I got bronze in Beijing so to move up to silver here it feels unreal,” said Watkin.
“I put everything from this morning aside because I knew I had to focus on tonight and I’m just so happy with that result.
“It’s such a short race, you don’t have any time to make an error so to equal my best is really good as well and something I haven’t done for a long time.”
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