Russian-born Rybakina went up 3-1 with a comfortable hold after fifth-seed Sabalenka dropped her serve with a double fault and sent a forehand long, but the Kazakh came under pressure and allowed her opponent to level the opening set at 4-4.
Rybakina hit back immediately, however, turning up the heat in gusty conditions at Rod Laver Arena to grab another break as Sabalenka double-faulted for a fifth time, and going on to seal the set with a big serve the Belarusian returned into the net.
It was the first time that Adelaide champion Sabalenka had dropped a set in 11 matches this year and the nerves began to show just a bit, before the 24-year-old composed herself and saved two breakpoints in the opening game of the next set.
Sabalenka then found a bit of consistency to break but had to overcome a wobble to grab a 4-1 lead after which she let out a huge roar and levelled the match with her 11th and 12th aces to take the match at Melbourne Park to a third set.
Sabalenka served with venom and hammered deep returns in the decider to punch holes through Rybakina’s defence for a 5-3 lead. She then double-faulted on one matchpoint and squandered two more before finally prevailing to claim the Daphne Akhurst Memorial Cup.
“I would like to congratulate Aryna … I know how hard you have worked for that,” said Rybakina. “Hopefully we’re going to have many more battles.
“I had goosebumps when everyone was cheering for us … I’m looking forward to coming back next year … It was an amazing two weeks for me and hopefully I’m going to have the same results and even better.”
