South Africa's spectacular stonewalling came unstuck in the final session as India cruised to a 337-run victory in the final Test to win the four-match series 3-0 at the Ferozeshah Kotla Stadium Monday. Beaten inside three days on either side of the rain-ruined second Test in Bangalore, Hashim Amla and his men had finally managed to take a Test into its final day with some dogged resilience. Resuming on 72-2, South Africa employed the same ultra-defensive approach that marked its batting Sunday, hoping to eke out a pride-salvaging draw than chase an improbable 481-run victory target. Amla (23) led the visitor's reply with his 244-ball resistance and AB de Villiers (43) battled for about six hours, much of it with a swollen thumb, before the slow-scoring tourists folded for 143 in 143.1 overs. Their single-minded blocking also allowed India's left-arm spinner Ravindra Jadeja to send down 17 consecutive maiden overs. Ravichandran Ashwin claimed 5-61 to finish with 31 wickets which also earned the off-spinner the man-of-the-series award. "All wins are pretty special but this one because we had to work harder for this," captain Virat Kohli said after India rose to No. 2 in Test rankings with the series victory. "We were surprised with the way they were defending the ball, but the bowlers didn't go off their plans. "It tested our patience but I think it's more special to get wickets in that situation," said Kohli. The Indian captain employed as many as eight bowlers, including himself, to overcome the Proteas' resistance and populated the crease with up to six close-in fielders for his spinners. Jadeja earned the breakthrough in the fifth over after the host had taken the new ball, spinning one past Amla's tentative bat to hit the top of the off-stump before embarking on a celebratory run. Amla departed after nearly five hours of defending, scoring 25 painstaking runs in what was the slowest ever Test inning of 200 or more balls. The 27 runs he added with de Villiers in 253 balls was also the slowest Test partnership of 175 balls or more. New man in Faf du Plessis displayed the same obduracy with the bat and took 53 balls — seven more than skipper Amla — to get off the mark. Jadeja ended du Plessis' (10) two-hour stay after lunch but it was once again Ashwin, the standout bowler in the series, who virtually sealed the match in India's favor by dismissing de Villiers soon after tea. It was one of the slowest innings by de Villiers, who holds the record for the fastest 50, 100 and 150 in one-day cricket, made more remarkable by the fact that he had been hit on the thumb by an Umesh Yadav delivery. "It was a tough series for our batters. Unfortunately we didn't manage to get that much runs most of the times," Amla said after South Africa's first away Test series defeat in nine years. Ajinkya Rahane was adjudged man-of-the-match for his twin centuries in the final Test of a series in which no other batsman managed to get to three-figures. — Reuters