As debuts go, it's hard to think of one as hectic as Jimmy O'Brien's.
Had everything gone according to plan for Andy Farrell, the Leinster back wouldn't even have played at the Aviva last night, but best laid plans are only that.
Initially named to the wing for Ireland A's meeting with the All Blacks XV on Friday night, a Robbie Henshaw injury that morning saw him promoted to the top team, albeit as a replacement.
Stuart McCloskey had taken Henshaw's place in the starting team, but the Ulster centre's return to Test rugby was cruelly ended after just 28 minutes when he injured his shoulder, after what had been an impressive showing in the Irish midfield.
Even then, O'Brien admits it was a surprise to get the call to tog out.
"Thank god we won because it would have made it a lot worse, I wouldn't be celebrating half as much," he said, having helped Ireland to a 19-16 win against the world champions.
"I'm just delighted to get my first cap, I thought I'd get two minutes at the end so to get most of the game and win is amazing."
The Kildare man showed his versatility by slotting in at outside centre, with the majority of his gametime at Leinster coming at either full-back or wing.
He looked calm in the thick of what was a ferocious game of rugby, playing a part in Mack Hansen's try in the second half, while he also stood up to the physical challenge with a vital one-on-one tackle on Eben Etzebeth in his own 22.
Looks can sometimes be deceiving, with Johnny Sexton telling reporters after the game that his Leinster teammate admitted he was "sh*****g it" when he got the call to come on just before the half-hour mark.
And when presented with the charge, O'Brien says his captain may have been embellishing things, if only a little.
"I think he might be adding legs to that story but first half I thought there was no way [I was coming on], I thought they'd bring Joey [Carbery] on and get Johnny to cover 12.
"There was a split second when I was maybe sh*****g it but got over that quickly," he added.
His versatility in the backline is a blessing for coaches, but it comes with a lot of work for the player.
With each position comes a different role in the attack and defence, and very little margin for error.
"Last night I sat down with Garry [Ringrose] on the off chance I was going to cover 13. Faz [Farrell] told me I was covering 13 so that was so helpful.
"I would say the camaraderie of the group is amazing. Everyone is so delighted, I was nervous about my first cap but the lads were so happy, they filled me with confidence being so relaxed about me playing 15, wing, 13, it speaks volume for the group we have.
"Straight away I was thinking of 13, had all the plays in my head for wing but went through the set plays from 13, went through the set-plays in my head, visualised the list I had in my notebook. I chatted to Garry, said, 'let’s do this', and from there it flowed. No one batted an eyelid which filled me with a lot of confidence."
And after a whirlwind 48 hours, the 25-year-old was able to savour the biggest day of his career with his family.
"It was amazing, I met my parents on the side of the pitch. My sister and my girlfriend were here, and then one or two of my good friends.
"It was just great to have them in the stadium to share the moment. They helped me through so much in rugby, it's just as big for them as it is for me."
