HARARE : Brendon McCullum slammed an unbeaten 81 as New Zealand raced to a 10-wicket win in the first Twenty20 international against Zimbabwe at Harare Sports Club on Saturday.The New Zealand bowlers set up the victory by restricting Zimbabwe to 123 for eight in their 20 overs after being sent in, with home skipper Brendan Taylor the only batsman to shine, making 50 not out. Opening bowler Kyle Mills and off-spinner Nathan McCullum took two wickets each in a steady New Zealand bowling performance.Brendon McCullum and Martin Guptill (40 not out) made the target look ridiculously easy, needing only 13.3 overs to score the required runs.McCullum thrashed six sixes and five fours off 46 balls as he confirmed his reputation as one of the world's most destructive hitters in the shortest form of the game. Guptill hit two sixes and two fours and faced 30 balls.Zimbabwe were hit by the late withdrawals of two key players, experienced wicketkeeper-batsman Tatenda Taibu because of injury and batsman Vusi Sibanda,whose mother died early on Saturday.Tall seam bowler Mills struck two early blows for New Zealand, dismissing both opening batsmen inside the first five overs. Hamilton Masakadza holed out to mid-off after hitting Doug Bracewell for six in the previous over and Chabu Chibhabha edged an attempted drive to wicketkeeper Brendon McCullum.Taylor and Forster Mutizwa added 28 for the third wicket before Mutizwa was leg before to left-arm spinner Luke Woodcock. Malcolm Waller tried to lift the scoring rate, hitting Nathan McCullum for six, but was caught at deep square leg in the same over. Charles Coventry also fell playing an ambitious shot against McCullum caught at cover.Hopes of a late flurry were dashed as three wickets fell off the final seven balls of the innings.Mills finished with two for 15 and Nathan McCullum took two for 17 but with the exception of one over from James Franklin which yielded ten runs, all New Zealand's bowlers proved difficult to score off.