The 22-year-old shipping science student was ecstatic as he came ashore after the two final races in the pre-medal series.
"This has been the greatest day of my life," a beaming Kontides said on Saturday after scoring second position overall in the 10 races, behind Australian favourite Tom Slingsby.
Kontides, who took a two-year break from his studies at Southampton University, has a big enough gap over his nearest rival to ensure he takes home silver.
He is due to compete in the 10-boat deciding medal race on Monday and still hopes he can make his country's first medal as an independent sporting nation a gold.
"Mathematically, gold is still possible. I have to try," he said, adding that he would use Sunday's rest day to recuperate and focus on tactics.
A medal is no longer on the cards for Olympic Laser champion Paul Goodison who is in sixth position. With a points tally of 87 has no chance of repeating his success of four years ago. The Briton has been on painkillers due to a back injury.
One of the sailors battling for the bronze medal in the final race will Kontides' friend Tonci Stipanovic of Croatia, who will be out to beat Sweden's Rasmus Myrgren to make it a real celebration for the training partners.
In the medal race, which will last about 30 minutes, sailors are awarded double points. Slingsby goes into the final race with 25 points and Kontides with 39.
"He (Slingsby) needs to be in the top seven and keep me out of the top three," Kontides said.
As a result, the Cypriot sailor thinks his Australian rival may try to "match race" him - the sailing equivalent of a duel - on the tricky Nothe course, where the winds are fluky but spectators get a great view of the sailing.
"He (Kontides) has sailed so well all week. He's had some great comebacks and you can't count him out," said Slingsby.
Asked if he felt any pressure to win gold after a disappointing medals showing so far for Australia in the Games, Slingsby said: "I am not just trying to win it for Australia, it is for myself. To win a gold medal would be a huge relief."
Kontides, whose family are due to join him in Weymouth on Saturday ahead of the medal race, has made huge strides since landing a 13th position in 2008 in Qingdao.
He said he relishes the stronger winds that dominated racing during the early stages of this Olympic competition, but was not phased by the forecast of lighter breezes.
Kontides made the most of the local knowledge he has gained from living in Weymouth during the run up to the Games and from sparring with Stipanovic, with whom he shares a trainer.
The Cyprus Olympic Committee became a recognised Authority in 1978 and joined the International Olympic Committee in 1979.
The country sent its first team to Moscow in 1980, but it has yet to win an Olympic medal and had set a goal of taking one home in 2012. The 13-strong team includes four in athletics, two sailors, a cyclist, a gymnast, three in the shooting team (skeet), a swimmer and a tennis player.
In the women's Laser Radial the field is more open going into the class medal race on Monday, with China's Lijia Xu leading on equal points with Dutch sailor Marit Bouwmeester and only one point ahead of early fleet leader Annalise Murphy of Ireland and Belgium's Evi Van Acker.
Britain's 470 sailors dominated a day of mixed fortunes for the home sailors as the men's and women's pairs both lie in the silver medal position, as does Nick Dempsey in the men's windsurfing.
The Elliott 6m women's match racing team of Lucy Macgregor, her sister Kate and Annie Lush qualified for the quarter finals despite two losses but hopes of a medal for Bryony Shaw in the women's RS:X look slim while Alison Young in the laser radial cannot finish higher than fourth.
Birthday boy Luke Patience was again in sparkling form with partner Stuart Bithell as they followed up four top four finishes with a third and a fourth in the men's 470.
Mat Belcher and Malcolm Page from Australia are favourites for gold and they showed their superiority with two race wins.
But the British pair are delighted with the way they have performed over the first three days to leave them just four points behind.
"The Australians cracked out a couple of race wins," said Patience. "They're racing well.
"But me and Stuart are happy today - we've come off with another great solid day and we're just in a great place right now and really happy with where we are at.
"If we can carry on doing what we're doing over the next four fleet races then it puts us in a fantastic position and I don't think we could have asked for much more at this stage of the game."
Hannah Mills and Saskia Clark came off the water with a fourth and a sixth and are just one point behind New Zealand sailors Jo Aleh and Olivia Powrie.
The pair, who won this year's world championships, are delighted with the way they recovered in race two after a technical fault held them up but they admitted they had not yet settled into the regatta.
"We're still well in the mix and that's where we planned to be by the end of day two so it's good," Mills said.
"But today the nerves were worse than yesterday for some reason - I don't think the late start is good for us.
"We both struggle to eat in the morning and so with a late start you are just sitting around waiting and trying to force some food into ourselves and struggling to so we'd like the 12 o'clock starts back.
"But as soon as we start racing we're fine it's just the waiting around we struggle with."
Nick Dempsey won a bronze medal in the mistral windsurfing class at the Athens 2004 Games, but could only manage an agonising fourth in the RS:X in Beijing in 2008.
This time he is sitting in joint second after a second and a third but leader Dorian van Rijsselberge is streaking away from the field with the lowest overall score of any fleet and Dempsey knows a silver is now his only realistic target.
He said: "They were two good results today, but with Dorian so far clear he can race freely as he has such a good score line.
"Unfortunately the guys behind me dictate what I do - it's the game we're in and at the moment it's about protecting the silver and chipping away at the German and the Polish guys and it will be the same again tomorrow.
"If there's a chance in the medal race to have a little play with Dorian and take him down I'll do my best to do that and then we'll see whether the gold medal is or not.
"I'm a little bit deflated by being behind but it is an Olympic Games and it's not easy but it was never going to be easy."
- Tom Slingsby