Guptill, Williamson make short work of Sri Lanka's 356
New Zealand 359 for 4 (Guptill 116, Williamson 88, Prasanna 2-63) beat Sri Lanka 356 for 8 (Tharanga 110, Boult 2-47) by six wickets
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Guptill smashed 10 fours and five sixes in his 76-ball knock of 116 while Williamson followed that up with a 60-ball 88. Both batsmen subsequently decided to retire out - Guptill in the 29th and Williamson in the 32nd - but by then New Zealand were 101 runs away at a required run rate of less than six.
Earlier in the day, Sri Lanka's batsmen fielded a batting-heavy outfit that posted 356 runs in their 50 overs. Upul Tharanga started the onslaught at the top, smashing 13 fours and three sixes to notch up a century. Kusal Mendis, at one drop, hammered seven fours and a six in his 50-ball 57 while Dinesh Chandimal - at two down- hit a quickfire 55.
It took Sri Lanka 15 overs to get to 100, another 15 to get to 200 and only 12 more to get to 300. That they managed to keep scoring at breakneck speed could well be attributed to their batting line-up. Of the nine batsmen used by them, only Nuwan Kulasekara's primary skill was that of a bowler. New Zealand, too, used nine bowlers but only Corey Anderson (0-39) and left-arm spinner Mitchell Santner (0-34) went for less than six an over. Despite taking two wickets, Trent Boult leaked 47 runs in his five overs.
Tom Latham (44) was instrumental in providing New Zealand a brisk start alongside Guptill with the pair adding 78 for the first wicket. Guptill and Williamson then took over, scoring 157 runs in 94 balls for the second wicket. Ross Taylor replaced Guptill with New Zealand at 235 for 2 in 29 overs, after which Neil Broom (37*) and Anderson - who reached his fifty with a six to finish the match - steered them home with 23 balls to spare. Of Sri Lanka's seven bowlers, only Seekkuge Prasanna's legspin managed to pick up any wickets. He finished with figures of 2 for 63 off his ten.