Henry had a double dose of good fortune, but well and truly made the most of it. Getting the nod to start was one thing, but then being able to walk out to a green wicket - with the support of a healthy slips cordon and stellar fielding outfit - would have been a dream scenario for the seamer.
He took full advantage, claiming a wicket with the second ball of the match, and then in his fifth over snaring the scalps of Kusal Perera and Kusal Mendis with back-to-back deliveries.
A famous hat-trick eluded him, but figures of 3-29 from seven overs was an excellent return, and one that will make him hard to drop for the clash against Bangladesh on Thursday morning.
However, Henry played down any talk of competition within the ranks, believing that everyone will need to be called upon across the eight – and potentially more – remaining games.
"That's the key about this World Cup, you're going to have to back your whole squad, and that's the beauty of this squad. We've been together a while now, and we're not necessarily looking at it as a competition, but what you can do best for the team. We all have our own skillset on the day with the wickets we're presented with."
For his part, Munro acknowledged that Nicholls was likely the first-choice opener for the Cardiff clash, but was delighted that he got his chance.
"I wasn't too sure but if Henry Nicholls was fully fit he probably would have got a crack there – it's a game of opportunities, you've got to take them when they come."
Take them he did, overcoming a slightly uncertain start to play with his natural aggression and form his first ODI century partnership alongside Martin Guptill.
After having made just one 50 in his prior 17 innings, Munro believes he made some important tweaks in training which could have him firing at the World Cup.
"I trained well for the two days here in Cardiff and got what I needed to do – I made a few adjustments in my technique a little bit, and it worked today, with my alignment towards the bowler, and trying to stay on each ball as well as I can."
Munro's game-changing power is something the Black Caps need to harness if they're to be able to match the Cup favourites, and his immense upside and tactical importance are advantages over Nicholls which will surely make it an alluring option to retain the 32 year old at the top.
They're not easy calls to make for the Black Caps – but at least this time, they're good problems to have.