Ashwin played four matches in the 2012 ICC World Twenty20 in Sri Lanka and took five wickets at an economy rate of 6 and an average of 19. During the first Test of England's tour of India in late 2012, Ashwin became the fastest Indian to record 50 wickets in Test cricket as he overhauled the milestone in his ninth game. India eventually lost the series 2–1 in which he struggled with the ball managing to take only 14 wickets in the four Tests at an average of 52.64. However, he scored 243 runs, averaging 60.75 per innings, including two fifties and finished as India's second best batsman of the series. In the three-match ODI series against Pakistan and the five-match ODI series against England, he took three wickets at 43.33 and seven wickets at 35.71 respectively. While playing for India Cements at the BCCI Corporate Trophy in February 2013, Ashwin worked with former Tamil Nadu spinner and childhood coach Sunil Subramaniam to make changes to his bowling ahead of the four-match Test series against Australia. Subramaniam and Ashwin spent a few hours every day for a week at the nets in Nagpur. Among the changes made was shortening Ashwin's bowling stride. Ashwin was highly successful on Australia's four-Test tour of India in February–March 2013. In the first Test at Chennai, his home ground, he took 7/103 and 5/95 leading India to a comfortable eight-wicket victory. He had a haul of 5/63 in the second innings of the second Test at Hyderabad where India registered an innings win. He took a total of four wickets in the Mohali Test where India sealed the series with a six-wicket victory. In the last match at Delhi, he took 5/57 and 2/55 in another Indian win which completed a 4–0 whitewash of Australia. During the match, Ashwin surpassed former India captain Anil Kumble's tally of 27 wickets for most wickets by an Indian bowler in a four-Test series. Ashwin finished the series as the leading wicket-taker with a tally of 29 wickets at 20.10 and won the Man of the Series award. It was the first time India won four or more Tests in a series and the first time Australia was whitewashed since 1969–70. Ashwin also became the third Indian off-spinner to take 25-plus wickets in a series after E. A. S. Prasanna and Harbhajan Singh.