The 24-year-old also impressed in the fourth test against India, returning to the XI after a modest showing at the Gabba in the second test.
Starc suggested it was a case of sticking to a technique that national bowling coach Craig McDermott helped tinker with.
"The ball is coming out nicely," Starc told the Nine Network. "I've been working on a few things over the last couple of months with Craig.
"It [rhythm] is something I've been working on, that run-up speed and the angle.
"It's nice to see some rewards."
Starc dismissed century-maker Rohit Sharma (caught by Glenn Maxwell on 138) with a full toss yesterday.
Far more impressive was Starc's masterful ninth over, when he captured the scalps of MS Dhoni (bowled for 19) and Akshar Patel (lbw for a duck) in a double-wicket maiden that curbed India's momentum.
Starc had the new ball swinging at the MCG, Shikhar Dhawan out edging in the opening over, caught by Aaron Finch for 2
"I love the white ball. It always goes one way or the other," Starc said.
"It was nice to see the bowling unit do a good job to restrict them to 260-odd on a pretty good wicket."
- AAP