Five times, Green had fallen between 74 and 84 in his embryonic Test career but shortly after lunch on the second day in Ahmedabad - after a somewhat uneasy interval sat on 95 - he was able to celebrate a significant milestone.
"You feel more like a Test cricketer when you've got that monkey off your back, so it is nice to tick that off in a way," he said. "It's so special."
"I think he's a fantastic player," Ashwin said. "Just the raw materials for a person as tall as him, lovely levers, good batting sense, can bowl and really hit the deck well, moves pretty well in the field. These are once in a generation cricketers you are talking about.
"I played a practice game against him at Drummoyne Oval in Sydney [on the 2020-21 tour]. From there on, I've been watching him bat, how well he moves to balls outside off, how well he comes down the pitch, how he sweeps the ball when he came to the subcontinent. As a bowler it's my duty to keep a check on all these things and also try to make a plan to try and make it uncomfortable for him."
It was some early feedback from Khawaja that helped set Green up to drive so imperiously during his innings as he took a particular heavy toll on India's two quicks.
"I think speaking to Uzzy, it was probably the ball coming back in where you might get your leg caught in the way and that might be the way to get out," Green said. "Having an experienced head down the other end, you can have these really in depth conversations and he gives you unreal info back.
"So spoke to him pretty early on, he said he recommends batting on leg stump and using your bat and looking to play every ball, whether its swinging in or swinging out.
"He's an experienced head that's played Test cricket for more than 10 years now, he's so valuable for guys like myself and a few of the young guys in the team the way he goes about it."
After a maiden five-wicket haul against South Africa at the MCG, in the game he suffered a broken finger, this century is another early high point in a career that continues to trend upwards but Green was eager to keep things in perspective.
"It's my 20th Test so I've had a good chance to see the ups and downs of Test cricket, see it for what it is," he said. "It's an incredibly tough game, and when you get moments like that you really cherish them. I've seen how tough Test cricket is and I'm enjoying every second of it."