Rabuka was elected with 28 votes to 27.
"It was a very close margin," Social Democratic Liberal Party (Sodelpa) youth forum president Ben Daveta said.
From the polls to parliament, every decision was balanced on a knife's edge.
First, no party gained an outright majority to rule.
Then it took the king-makers Sodelpa two split-votes to choose a coalition partner -- and even in the final secret ballot to elect a prime minister, someone in the opposition ranks voted for the other side.
It has been a frantic time, Daveta said.
"Well, first of all, I've really been trying to get my breath for the last few minutes and it was nerve-wracking.
"Democracy came through, their prayers came through."
Prominent Sodelpa member and democracy advocate Pita Waqavonovono said this is the way forward.
He expressed a sense of excitement to 'make Fiji better again'.
"It is time for us to have a real democracy and FijiFirst has shown an unwillingness to govern democratically," Waqavonovono said.
In its first 100 days Rabuka's government must find a way to unite Fijians and tackle the challenges of a nation emerging from the pandemic.