The S&P/ASX 200 index closed flat at 7,394.3 points, but remained near an all-time peak hit earlier in the session.
The most populous state of New South Wales, home to Sydney, on Monday reported a rise in fresh COVID-19 cases despite an ongoing stay-at-home order.
Mining stocks jumped as much as 1.5%, boosted by strong iron ore prices as a recovery in steel margins in China buoyed sentiment.
Global miners BHP Group and Rio Tinto advanced 1.3% and 2.5%, respectively.
Meanwhile, energy stocks dropped 1.4% as oil prices fell on concerns about fuel demand from the spread of COVID-19 variants and floods in China.
Oil & gas explorers Woodside Petroleum and Santos lost 1.4% and 1.9%, respectively.
Gold stocks fell to their lowest since April 7, hurt by weak bullion prices, with largest-listed gold miner Newcrest losing 1.5%.
“Investors are now looking for news to propel the market firmly into record territory”, said James Tao, a market analyst with CommSec.
“In the short term, though there is a bit of uncertainty… participants will continue to look at the Sydney restrictions, and what that could mean for the country’s economic recovery.”
Beleaguered casino operator Crown Resorts plumbed near half-year lows as a Western Australia Royal Commission inquiry into its Perth operations was extended to March 2022.
Lynas Rare Earths was the biggest gainer on the benchmark index, after posting a record quarterly revenue.
New Zealand’s S&P/NZX 50 index fell 0.5%, hurt by losses in financial and consumer stocks.
