Wellington: Kane Williamson became the number one-ranked Test batsman as New Zealand secured the two-match series 2-0 after comprehensively defeating Sri Lanka by five wickets on day four of the second match in Hamilton on Monday.

Resuming at the overnight position of 142-5 and requiring another 47 for victory, New Zealand wrapped up the match under an hour without losing another wicket, with Williamson remaining unbeaten on 108 and BJ Watling unbeaten on 13, Stuff.co.nz reported.