Lyon broke India's back in the 1st innings with Rahane's wicket in the very 1st over of the 3rd day. This wicket potentially changed the course of the match, instead of getting a lead, India couldn't even reach Australia's total. And now in the second innings, he broke India's back again by getting Virat's wicket which kind of defined the outcome of the match. He even got Vijay, who looked solid in this innings. We got to accept, Lyon has been exceptional. At the same time, even if India had a spinner, I'm not sure if he could have created the same impact as Lyon!
Talking about Pant, in the 19 deliveries he played today, 5 were mishits. He looked like he would get out any ball, and this was with a reasonably old ball. Imagine what happens if he was facing a brand new ball!