At stumps on Day One, Australia were placed comfortably at 283/3 with Labuschagne and Matthew Wade batting on 130 and 22 respectively.
The highlight on Day One of Australia's batting was the 156-run third-wicket partnership between Labuschagne and Steve Smith. However, just when Smith was looking to score his first century of the series, he was dismissed for 63.
Earlier, Tim Paine elected to bat on a placid Sydney wicket which doesn't seem to have much for the bowlers. The match started with tributes to the firefighters battling catastrophic firestorms around the country.
The crowd at the SCG rose to its feet to join both the teams in a minute of applause to honour the volunteer firefighters before the start of play and players wore black armbands.
The hazardous fires have affected thousands of people in New South Wales, with the state declaring an emergency for the third time in as many months. Cricket Australia have declared that if the smoke from the fire reaches SCG, they will pull the players out of the field.
As a result of the viral illness that laid low captain Kane Williamson, batter Henry Nicholls and spinner Mitchell Santner -- as well as the hand injury suffered by Trent Boult and the decision to drop his fellow seamer Tim Southee -- the Black Caps fielded five new players from the Melbourne Test a week earlier.
David Warner and Joe Burns started the innings cautiously and added 39 runs for the opening wicket before Burns was dismissed by Colin de Grandhomme for his individual score of 18.
Warner then tried to build another partnership with Labuschagne before he was caught at leg gully after scoring 45.
Smith -- who made his slowest start in Test cricket consuming 39 balls to get off the mark -- then took the mantle alongside Labuschagne and the duo stitched together a 156-run stand for the third wicket, thus tiring the New Zealand bowlers.
Labuschagne, during the course of the partnership, became the first to reach triple-figures in 2020. After the fall of Smith's wicket, Wade joined the proceedings with Labuschagne and took the team towards the end of the day's play without any hiccups.
Brief Scores: Australia 283/3 (Marnus Labuschagne 130*, Steve Smith 63; Colin de Grandhomme 2/63)