They continued the recipe in the second set - with some wonderful play from both teams. One point in particular, where the New Zealanders defused three consecutive smashes with defensive lobs then won the point, brought the crowd to their feet.
8:35pm
Vasek Pospisil has prevailed 7-6 (4) 7-5 over Karlovic, for his second successive win over the giant Croatian, after a straight sets win in Basel in 2013.
Karlovic's early exit is unfortunate for the large Croatian contingent in the stand, who provided plenty of vocal support in Karlovic's first appearance here.
8:15pm
A battle of the big serves on centre court, with Croatian Ivo Karlovic taking on Canadian Vasek Pospisil. At 2.11m, Karlovic is a fearsome proposition and the 36-year-old served more aces last year than any other player on the ATP tour.
World No 39 Pospisil matched him well - and after the first set inevitably progressed to a tiebreak - won the breaker 7-4.
The Canadian leads 6-5 in the second set.
4:50pm:
Jack Sock has waltzed into the second round of the ASB Classic, dispatching of Victor Estrella Burgos 6-0 6-4 in 49 minutes. Burgos improved in the second set - managing to hold serve on four occasions - but struggled to contend with the power of the American, who was deadly accurate from the back of the court.
Sock is coming off a fantastic year 2015, where he won his first ATP title (Houston), made the final in Stockholm and reached a career high ranking of 26.
1:45pm:
Donald Young has completed the win - after a few wobbles in the second set - 6-2 6-3 in just over an hour.
It was a decent effort from the Finn Tearney, in his first singles match at this level.
There was a gulf in ability, but not a tremendous one. Tearney showed enough to give hope that he can continue his rise up the rankings in 2016, though obviously the climb gets much steeper as you get closer to the top 200.
1:05pm:
Tearney has lost the first set 6-2 in just under half an hour. The Kiwi is competing well in most games, but the lack of polish - that you would expect - is undermining his efforts.
Tearney has produced some lovely shots but is struggling to live with the American's power from the baseline.
He was broken early in the second set and currently trails 3-0.
12:40pm:
The men's version of the ASB Classic is underway for 2016, with New Zealander Finn Tearney in action against Donald Young on centre court.
Tearney had a remarkable year on the lower reaches of the ATP tour - rising over 1000 places to 363 in the world. That was enough to earn him a wildcard into this tournament but the
He's in action today against world No48 Donald Young. The American was once touted as the next big thing, with some noteworthy success in Juniors but has yet to achieve on that promise.
After being broken in his first service game, Tearney has just broken back to trail 3-2 in the first set.
- Michael Burgess