A win for Alex de Minaur and loss for Thanasi Kokkinakis have left Australia level at 1-1 with Hungary in their Davis Cup qualifying tie after day 1 in Sydney.

Australia's hopes of progressing to the 2022 Davis Cup Finals hang in the balance after Lleyton Hewitt's men split the opening singles rubbers in the qualifying tie against Hungary in Sydney.

Alex de Minaur gave Australia the early initiative with a 7-5 6-2 victory over Zsombor Piros on Friday night before Thanasi Kokkinakis lost 7-6 (7-4) 1-6 6-3 to veteran Hungarian spearhead Marton Fucsovics.

The two teams will return to Ken Rosewall Arena on Saturday to wrap up proceedings with the doubles and two reverse singles matches.

Hewitt has pinned his faith in Cup debutant Luke Saville to partner John Peers in the doubles clash with Fucsovics and Fabian Marozsan.

Regardless of that outcome, the tie will still be alive when de Minaur takes on Fucsovics in a high-stakes showdown between the two countries' No.1s.

"Before the tie, that was probably the match a lot of people were waiting for," de Minaur said.

"We had a battle last Davis Cup and we get to do it again.

"We're both playing for pride and passion and for our country ... let the best man win."

Fucsovics faces a huge day-two workload, having to back up for three matches in less than 24 hours.

"I will play the doubles. I hope to have a long sleep tonight," he said.

Hewitt said he admired the world No.35's commitment but warned he might have bitten off more than he can chew.

"For anyone to play all three now. To back up, whether you've played one or two singles, it's not easy," Hewitt said.

"It's something on the tour that you never have to do. You never play doubles before you go out and play singles.

"He obviously is going to do absolutely everything in the power to try to get the win for his team and good on him.

"But I know one thing for sure: Alex won't be making it easy for him in that fourth rubber."

Should the tie go down to the wire, Kokkinakis said he should be ready to play against Piros - assuming neither captains change their line-ups - despite needing treatment for a hamstring strain during his loss to Fucsovics.

Playing on his "favourite court in the world", de Minaur didn't have it all his own way against Piros, the world No.240.

Despite his lowly ranking, Piros beat John Millman in Australia's hard-fought 2-1 victory over Hungary in the 2021 Davis Cup Finals in November.

And he pushed de Minaur too, Australia's world No.30 under pressure throughout the first set before taking it with the only service break in the 12th game.

The second set was more straightforward, de Minaur breaking Piros again in the fourth game, consolidating for a 4-1 lead and sealing the match after one hour and 23 minutes.

Playing his first Davis Cup match since the 2015 World Group semi-finals against Great Britain, the injury-plagued Kokkinakis needed his medical timeout after falling behind 3-0 in the third set against Fucsovics.

He broke back upon the resumption, only to drop serve the very next game to trail 4-2.

This time there was no coming back for Kokkinakis, whose defeat leaves the tie on a knife edge.