Then again, on the back of a week-long camp in Potchefstroom which removed the excuse of rust from the equation, it wasn't flash either.
All post-match comments agreed on one thing: Zimbabwe deserved the seven-wicket success, Craig Ervine's maiden ODI century carrying the hosts to a rousing win with an over to spare.
That being so, stand-in skipper Williamson still can't have been impressed at his team's inability to defend 303 against the perennial lightweights even in their own backyard.
And it throws light on the issue of how far dwon New Zealand's bowling depth reaches. There's a tendency to think New Zealand are not badly off in most departments right now.
Yesterday's first-up effort by the bowling group shorn of new ball spearheads Trent Boult and Tim Southee would suggest otherwise.
The three seamers, Matt Henry, Mitch McClenaghan and Jimmy Neesham, collectively produced figures of 25-0-149-0.
Offspinner Nathan McCullum did get all three wickets but went at a blink under seven an over, while it was a tough day for Ish Sodhi's ODI debut.
Speedster Adam Milne and Ben Wheeler were sitting in the stand yesterday. Their chance could come in the second game of the three-match rubber at the same venue tonight.
Williamson and Ross Taylor should have been celebrating another quality collaboration in New Zealand's innings.
They are racking up serious numbers to rank among the best pair of batsmen in the ODI game right now.
They are the 15th pair to have ticked off 10 century stands; Taylor's 112 not out lifted him to 27 international hundreds, level with Nathan Astle, and he's one behind the highly successful former opener on 15 ODI tons.
As for Williamson, he's developing a worrying tendency to get out in the nineties. Cricketing economists would doubtless call that a First World problem.
Three times since the start of the England ODI series Williamson has been dismissed between 90 and 97. In that period he's made 503 runs at 83; Taylor's numbers for the same six games are 487 runs at a whopping 121.7.
He's already rattled on four centuries this year, the most by a New Zealand batsman in a calendar year - he made three last year while Williamson has three in 2015.
Zimbabwe's successes are rare and they are right to celebrate rousingly. Their problem is lack of consistency but as New Zealand discovered yesterday - as they did four years ago at Bulawayo - when they get it right, and their higher-regarded opponents are muddling their lines, Zimbabwe can upset the best-laid plans.
New Zealand would have wanted a straightforward, albeit fairly testing, sweep of Zimbabwe as preparation for facing South Africa this month.
Now they have a battle to win the series. That doesn't sound like the team who steamrollered to the World Cup final five months ago. Time to raise the bar.
