New Zealand 162 for 3 (A Kerr 66, Bates 56) beat Sri Lanka 60 (A Kerr 2-7, Tahuhu 2-12) by 102 runs
New Zealand thumped Sri Lanka so severely in each team's last match of the group stage, in Paarl, that they nullified the terrific start Sri Lanka had to the tournament, and gave themselves a chance of qualifying for the next stage, despite their own underperformance in their first two games.
But Sri Lanka are out of the competition, despite having delivered an upset to South Africa to start their tournament, before also beating Bangladesh. They have never made it out of the group stage in a T20 World Cup.
New Zealand's 162 for 3 was made possible by Sri Lanka's repeated fielding mistakes - at least two dropped catches, and as many missed run out chances. But it was not an unattainable score, until Sri Lanka's top order crashed and burned in the space of 4.5 overs - the first five wickets going down for the addition of 13 runs.
The collapse rolled on, and Sri Lanka were all out for 60 inside 16 overs. Seamer Achini Kulasuriya, who appeared to badly injure her shoulder while delivering her third over, could not bat.
Kerr and Bates dominate
Bates and Kerr's 110-run second-wicket partnership, which came off 83 deliveries, was the centrepiece of their victory. Bates had been the quieter of New Zealand's openers in the powerplay, letting Bernadine Bezuidenhout create the early momentum with her 32 off 20 balls. But in the company of Kerr, she began to settle into a substantial innings. She struck Kavisha Dilhari for consecutive fours - one through deep third, the other through deep midwicket - in the ninth over, and appeared particularly at home at the crease.
Kerr, meanwhile, seemed comfortable from the outset. She struck her third ball - from the experienced Inoka Ranaweera - to the boundary, and breezed her way through the middle overs, venturing only the occasional boundary on a pitch not particularly suited for big runs. At the end of the 14th over, she was 31 off 29, and then began to attack more seriously, finding frequent boundaries in front of square, as she muscled the Sri Lanka bowlers through the leg side with particular relish.
They were both dismissed in the final over, but despite not having hit a six between them, had inflicted sufficient damage.
Sri Lanka's woeful fielding
Sri Lanka should have had Bezuidenhout out for 7 when she had been stranded mid-pitch in the third over. But Kulasuriya's throw from backward square leg was wayward and wicketkeeper Anushka Sanjeewani could not collect.
Bezuidenhout should have been out two overs later too, for 19, had Harshitha Samarawickrama held a catch at deep midwicket, off the bowling of Malsha Shehani. But she let the straightforward chance slip through her fingers.
Bates was also a benefactor of Sri Lanka's fielding largesse. She was dropped on 37 by Nilakshi de Silva - a skied chance to mid-on going down. Then in the 16th over, on 41, she could have been out again, had either the fielder at midwicket or the bowler who collected the ball made more accurate throws.
But what pressure the Sri Lanka bowlers did create did not translate into wickets on account of their fielding.
Catastrophic collapse costs SL
Although New Zealand had made more runs than they ought to on a difficult surface, a target of 163 was not completely beyond Sri Lanka, particularly if their openers got going. Neither did. Sri Lanka struck only one boundary in the powerplay, as Jess Kerr, Hannah Rowe, and Eden Carson delivered tight early overs.
And once the wickets started to fall, they went rapidly. Harshitha was caught in the outfield at deep midwicket, trying to slog her first boundary after a frustrating start. Vishmi Gunaratne was out next over, when Bates completed a spectacular catch running back from mid-on. De Silva had her leg stump rattled by a Jess Kerr yorker.
And when captain Athapaththu was out for 19 in the seventh over, lbw on review against a straighter delivery from Amelia Kerr, Sri Lanka were always going to struggle.
Had they made in to 123, they could still have finished ahead of New Zealand on NRR and given themselves some chance of qualifying for the semi-finals. But Sri Lanka's middle order had not produced significant runs even in their wins. And here, they fell rapidly.
Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @afidelf