Kane Williamson scored his second Test century and guided New Zealand to an unexpected draw as the host made 200 for six at the end of the third and final Test against South Africa at the Basin Reserve Tuesday. New Zealand had been chasing an improbable 389 for victory and Williamson showed maturity beyond his 21 years after his more experienced colleagues were destroyed by Morne Morkel's career-best figures of 6-23 that had taken the visitors within sight of a crushing win. South Africa's fielders did not help themselves, dropping four catches. Williamson's century was the first by a New Zealander during the series. South Africa's batsmen scored five. Doug Bracewell was 20 not out at the end of the match, blocking four deliveries of Vernon Philander's final over before the umpires ended the match. The hosts had needed 389 from 81 overs after Graeme Smith declared at 189-3 an hour into the day but Morkel had destroyed New Zealand's top order by tea. The tall fast bowler entered the break with figures of 5-11 from 11 overs, leaving the home side flailing at 103-5 and needing to see out another 38 overs to save the match. Williamson and Kruger van Wyk combined for an 80-run partnership that got New Zealand to a position where they had less than 20 overs remaining to survive. Van Wyk became Morkel's sixth victim when he hit the ball directly back to bowler. The wicket surpassed his previous best of 5-20 against India at Centurion in Dec. 2010. Williamson and Bracewell then saw New Zealand through to safety, with Williamson bringing up his second Test century with a dangerous single. The day, however, belonged to Morkel, who dashed any improbable hope of a New Zealand victory when he dismissed Daniel Flynn and McCullum, both for nought, before lunch. He then had Martin Guptill caught by Jacques Rudolph for 14 and then bowled Dean Brownlie (15) and Daniel Vettori (nought) on successive balls in the middle session.