Nadine de Klerk and Masabata Klaas starred with the ball as the Proteas clinched an ODI series victory over Pakistan in the second ODI on Monday.South Africa cruised to a six-wicket victory at the National Stadium in Karachi.The Proteas take a 2-0 lead in the three-match ODI series, with the final ODI scheduled for Thursday.Chasing 169 for victory, the Proteas started off well with a 41-run opening stand before skipper Laura Wolvaardt fell for 13 off the bowling of Sadia Iqbal.Tazmin Brits then shared a 40-run stand with Lara Goodall before Brits fell five runs short of fifty, ending on 45 off 54 balls (hitting four fours and a six).Goodall made a valiant 36 before she was caught off Umm-e-Hani.Iqbal took her second as she got the wicket of Sune Luus for 10.However, an unbeaten 54-run stand between Marizanne Kapp (29*) and De Klerk (24*) saw the Proteas easily reach the target with 96 balls to spare.Earlier, who Pakistan won the toss and decided to bat first, got off to a shaky start with the introduction of De Klerk.De Klerk took two wickets in two balls removing Muneeba Ali (4) and Sadaf Shamas, who nicked behind to the keeper for a golden duck.The Proteas all-rounder took her third, bowling opener Sidra Ameen as wickets continued to tumble with Ayabonga Khaka and Masabata Klaas chipping in.The hosts soon were reeling at 49-6 before a 114-run partnership between Aliya Riaz and Fatima Sana saved Pakistan some blushes.Sana brought up her maiden ODI half-century as she top-scored with 69 off 87 balls (hitting 10 fours) before she was stumped off the bowling of Nonkululeko Mlaba.Riaz continued her fine form as she hit her seventh ODI fifty, scoring 53 off 86 balls (hitting three fours) before she was caught off Klaas.De