World Cup debutants South Sudan, who played their first official international game only six years ago and are ranked 62 in the world, beat Angola 101-78 in Manila to claim their third win of the competition.
Nearest challengers Egypt then lost 88-86 to New Zealand to hand the sole African qualifying berth on offer for the Paris Games to South Sudan.
The country has lurched from one crisis to another since winning independence in 2011, but the team's World Cup performances have captured the public's imagination, with crowds gathering to watch on giant screens in the capital Juba.
An emotional Ivey said they had brought "unity, camaraderie, love and friendship" to the country.
"This team is a beam of light," he said. "This country has only been independent for 12 years. To do this is incredible. I take my hat off to my players because they trusted us from day one."
South Sudan have won plaudits for their dynamic play and positive attitude on and off the court at the Basketball World Cup being held in the Philippines, Japan and Indonesia.
They pulled off a historic win when they beat basketball-obsessed China in their second game, before downing the Philippines in the classification stage.
Only 12 teams will take part in the Paris Olympics men's basketball competition, with France qualifying automatically as hosts.
South Sudan captain Kuany Ngor Kuany said he was proud to "create history" by representing his country.
"We've had a lot of athletes representing different countries under different flags," said Kuany, who was born in South Sudan but moved to Australia as a nine-year-old. "For us to be able to do it for the first time as a country really means a lot, and that's why we were fighting so hard to be able to get that opportunity."
Chicago Bulls points guard Carlik Jones scored 26 points and had 15 assists and 7 rebounds against Angola.
Marial Shayok scored 18 points and Nuni Omot, who was born in a refugee camp in Kenya, where his parents spent three years after travelling more than 400 miles to flee civil war in Ethiopia, scored 17.
The impetus for South Sudan's team came from Luol Deng, a former NBA player who was born in Sudan and raised in London after his father, a former Sudanese government minister and political prisoner, was granted asylum by the United Kingdom.
Deng spent 15 years in the NBA before becoming president of South Sudan's basketball federation after he retired.
American-born Ivey, an assistant coach for the Houston Rockets in the NBA, said Deng "put this together".
"A year ago we were practising outside with eagles flying around, the courts were flooded," he said. "To go from there to play in front of these fans in the Philippines, I'm on cloud nine right now. It's a great feeling."