New Zealand responded maginificently from their 203-run defeat in the final ODI by posting an imposing 189-5 at Eden Park. While McCullum's unbeaten 60 and man-of-the-match Luke Ronchi's unbeaten 48 were key elements, the captain said it was a superb all-round performance that sealed the first win in the two-game series.
"I thought the way we played today is pretty close to how we want to play as a short-version team," McCullum said.
"I think our bowling was very good when it needed to be. I thought our execution still needed some work but at least we had some pretty sound plans."
McCullum and Martin Guptill were both outstanding in the field, with the New Zealand captain letting nothing past before Guptill's two difficult chances, including one that needed a perfectly-timed jump to avoid it going over his head for six.
"I thought our fielding was brilliant. Obviously the catches were outstanding but those happen when the rest of your fielding performance was top drawer."
The skipper acknowledged Colin Munro's 12-ball 22, saying it helped give the hosts some momentum with the bat as they went about smashing 119 from the final 10 overs to set up the intimidating total.
Fast bowler Adam Milne was also in line for some praise from the captain, with his superb display that included deliveries bowled at 153kph exciting the Eden Park crowd on Saturday.
"He has bowled reasonably bowled for us without much luck. He's probably had his best performance in a black shirt."
The serie shifts to Wellington's Westpac Stadium for the T20I series decider and McCullum said there was an opportunity to right the wrongs of the ODI decider in Hamilton.
"If we're serious about winning tournaments then you've got to be closing out those sorts of games. Wellignton presents a big challenge for us and I'm looking forward to seeing how we respond."