As far as days go, it was something of a doozy for Matt Renshaw, with lots of firsts.

Playing your first Test in India? Check.

Facing the world's two highest-ranked bowlers for the first time? Check.

First occasion dealing with a spinner in the opening overs? Check.

Making your first Test half-century outside Australia? Check.

Suddenly feeling your tummy lurching like a lopsided rickshaw, realising you're not going to make it to lunch without suffering an embarrassing accident on live television, having your bowel movements (figuratively) dissected by viewers all over the world after you've left the field and copping a barrage of criticism - most notably by a former Australia captain - suggesting you were a bit soft?

Check. Mate. Maaaaaaate.

Matt Renshaw has taken most tasks in his stride since he was elevated to the Australia Test team in November, but facing R Ashwin and Ravindra Jadeja on a raging Pune turner with a dodgy gut was a significant challenge.

Renshaw's inexperience wasn't evident in the way he patiently saw off the new ball in the first session, but his callowness did mean he was unsure of his options within the Laws of the game when he realised he was unlikely to last until lunch.

"It came pretty suddenly, probably about five or ten minutes before Davey [David Warner] got out," Renshaw said. "I asked Richard [Kettleborough] how long there was till lunch and he gave me the answer of half an hour. I was struggling a bit then. It wasn't an ideal situation to be in.

"It was tough. I wasn't sure of the ruling. I didn't know you could retire ill, so thought I'll just get out there and make sure I batted till lunch. It wasn't an ideal situation, so I just had to make do. And then coming back, it was probably a bit strange for me, waiting to bat, because as an opener you just go straight out there to bat, so probably that was the most challenging bit, waiting to bat."

Steven Smith, who had just come to the crease at the fall of Warner's wicket "wasn't too thrilled" when Renshaw ran off, but, according to the opener, once Smith realised the predicament, he understood. "He didn't really understand what was going on at the start, I sort of just ran past him, he didn't really comprehend what was going on. I told him I needed the toilet. Obviously, we'd just lost a wicket, so there would be two new batsmen out there, but as I said, it's a hard scenario to be in and he understood. We've had a chat now and we're all good.

"I felt quite bad knowing that I could be letting the team down, so that's why I went back out there. I wanted to do my bit for the team and wanted to make sure we had a pretty good day."

If Smith was sympathetic, Allan Border was not. The former Australia captain was scathing in his assessment of Renshaw's decision to leave the field. "I hope he's lying on the table in there half dead," Border said on Fox Sports. "Otherwise, as captain, I would not be happy."

Renshaw brushed off the criticism, turning it aside as deftly as he had India's bowlers throughout the morning. "I guess that's just something he grew up with and that was his sort of mentality," Renshaw said of Border. "Steve was good and he understands that 'when you need to go to the toilet, you've got to go to the toilet'."

After squirting an edge through the slips to the boundary in the first over of the match, Renshaw did the bulk of his scoring through the on-side, remaining watchful when facing Ashwin and going on the offensive to Jadeja when he came into the attack and turned the ball into the left-hander. On a pitch that unsettled older and more experienced team-mates, it was a solid tactic, admirably executed.

"I've never seen a pitch like that," Renshaw said. "So I went with a pretty open mind and I tried to do just what I normally do in Australia, which is bat as long as possible and weigh the bowlers down. It's probably a bit harder to weigh them down if they're spinners, but I think I just tried to keep my plan simple against each different bowler."

Despite losing nine wickets on the opening day, Renshaw was upbeat about Australia's batting performance. "Yeah, I think we had a really good day. The fact that we had the 50-run partnership at the end of the innings. We've talked about how the top-order needs to score runs, but especially the tail needs to hang on and get some bonus runs (so to speak). I think we've had a great day and it's a good confidence builder."