Chennai were on a franchise record five-match Indian Premier League losing streak, while Lucknow were eyeing a fourth success on the bounce.
But on Monday night, the IPL formbook was ripped up and thrown out of the window as Chennai pulled out a five-wicket victory.
That was despite Marsh, 33, who has been in sublime form in the formative days of the new IPL campaign, doing everything in his power to avert an upset in front of the home support in Lucknow.
Marsh had missed Saturday's six-wicket defeat of Gujarat Titans to be with his 19-week-old daughter Olive, who was unwell.
But quickly back in harness, he overcame the first-over departure of fellow opener Aiden Markram to reach 30 off 25 balls, including two sixes and two fours.
Bouncing back from being dropped by Australia's Test team after returning six single-figure scores in seven innings against India in the summer, Marsh had blasted IPL scores of 72, 52, 60 and 81 before Monday night's assignment.
But after a half-century stand with Rishabh Pant had Lucknow heading in the right direction, hopes of another 50-plus rampage by Marsh were cut short when he was bowled by Ravindra Jadeja after 46 minutes at the crease.
Although Pant powered on for 65, Lucknow's 7-166, their lowest total of the season, looked vulnerable and they were duly made to pay.
The ageless Mahendra Singh Dhoni scored a robust 26 not out off 11 balls to get Chennai over the finish line with three balls to spare. Chennai remain at the bottom of the table, with Lucknow fourth.
