Kane Williamson had New Zealand on the brink of victory after a spectacular Sri Lanka collapse on the third day of the second Test in Hamilton today.New Zealand were 142-5 at the close of play, requiring a further 47 runs to claim the Test and sweep the series. Shortly before lunch on the third day their hopes of a win seemed remote with Sri Lanka 126 runs ahead and with all second innings wickets in hand. But the tourists' fortunes swung from commanding to catastrophic when the 10 wickets fell for 62.New Zealand went from being 55 behind on the first innings to chasing a target of 189 to win. Williamson was not out on 78 at stumps, in sight of his 13th Test century with BJ Watling yet to score.