Australia's Queensland state has voted to keep its centre-left government after a race dominated by debate over strict measures to prevent coronavirus spreading in the popular tourist playground.

Queensland, home to the Great Barrier Reef and known as the "Sunshine State" for its inviting weather, became a national battleground over virus prevention after its decision to shut its borders to other states to keep out Covid-19.

State Premier Annastacia Palaszczuk -- who has been heavily criticised by Australian Prime Minister Scott Morrison and his conservative government over the impact of border closures on Queensland's large tourism industry -- claimed victory late Saturday.

The win will write Palaszczuk into the history books as the first woman to win three elections in Australia, and by mid-2021 she will become the longest-serving female leader in the country's history.

"We stood strong, Queensland," she told supporters in Brisbane late Saturday.

"We stared down critics and we have come out of it all the better for it."

Palaszczuk's government held a slim one-seat majority in the 93-member parliament heading into the election.

With just over 60 percent of the vote counted, public broadcaster ABC predicted her Labor party could pick up an additional four seats after a five-percent swing in its favour. 

Morrison -- whose strong support in Queensland propelled his own election victory last year -- spent a week on the campaign trail for Palaszczuk's opponent, arguing that opening internal borders was necessary for the country's economy to recover from a coronavirus-induced recession.

Australia has been relatively successful in containing Covid-19, recording just over 27,500 cases and 907 deaths since the pandemic began, but was sent into its first recession in nearly 30 years after a national shutdown in March.

A second wave in Victoria state sent Melbourne's five million residents back into lockdown in July, but the city has now begun reopening after bringing the outbreak under control.

Morrison's government closed Australia to international visitors in March, saying free movement across the country's borders would not resume until a vaccine is found.