Lagos, Nigeria (CNN)It was the ultimate David versus Goliath battle.
Two female South African activists working for small NGOs took on the South African government. They won a legal challenge that stopped a $76 billion dollar nuclear deal with Russia.
For their herculean efforts, Makoma Lekalakala, 52, and Liz McDaid, 55, were awarded the prestigious 2018 Goldman Environmental Prize on Monday.
"These were hard won gains," Lekalakala said on being awarded the Goldman prize. "But for us the whole thing was about holding our leadership accountable to the people. We really fought for it."
The highly-coveted Goldman prize is awarded annually to six people from six different continents who undertake "sustained and significant efforts to protect and enhance the natural environment, often at great personal risk."
The activists challenged the proposed nuclear deal in court on the grounds that negotiations were kept secret and an agreement was reached without parliamentary debate in South Africa.
In a landmark ruling on April 26, 2017, a High Court in Cape Town pulled the plug on the nuclear deal, declaring it unlawful and unconstitutional.
Other nuclear power deals South Africa had signed with corporations in the US and South Korea were also voided by the court.
The government's attempt to put the state power utility company Eskom in charge of procurement instead of the country's electricity regulator was also declared illegal.
The ruling also stated that all nuclear proposals in South Africa must get a public hearing and parliamentary approval.
The energy minister at the time said it would not appeal the case and indicated it would seek new deals with parliament consultation. "We will try our level best to start signing new agreements," said Minister Mmamoloko Kubayi-Ngubane in a statement.
Suing the South African government was the last thing on their minds when the pair stumbled upon the secret deal in 2014.
But the government's reluctance to answer questions forced Lekalakala and McDaid to take the case to court.
"We just had to take a different route," Lekalakala says.
For almost two years, Lekalakala and McDaid held public protests, brought other environmental lobbyists into their fold and mobilized a strong campaign force of mostly women.
"Women were able to understand very quickly the link between having not enough money right now at a household level to buy electricity and the problem of having even more expensive electricity if the nuclear deal went through," McDaid says.
"It was actually quite affirming that people were recognizing the role that women could play in such a campaign."
"Little money was raised because people were saying this is risky, nobody wanted to be linked to having supported this court case," Lekalakala says.
They found a lawyer, Adrian Pole, who agreed to take the case on pro bono, buying them time against the government's attempts to stall the case.
"The government, they tried to wear us out and hoped that we run out of money for the lawyers," McDaid says. "In every step of the legal process they would ask for a delay."
In 2014, South Africa, then under the leadership of Zuma, appointed Russian energy company Rosatom to build nuclear plants worth one trillion rand ($76bn). When completed, the project would yield 9.6 GW of power, according to government figures.