The 29-year-old Ashwin completed 150 Test wickets on Friday (November 6) at the PCA Stadium and with this milestone became the fastest Indian to reach there.
When Ashwin dismissed South Africa's last man Imran Tahir (caught by Cheteshwar Pujara), he reached 150-wicket mark in his 29th Test. He has 100 wickets at home, which is also an Indian record.
Ashwin had figures of 5/51 as India took a slender 17-run lead, bowling South Africa out for 184. It was Ashwin's 13th five-wicket haul in Tests.
He equalled Hugh Tayfield (South Africa), Ian Botham (England), Dale Steyn (South Africa) and Saeed Ajmal (Pakistan). All of them took 150 Test wickets in 29 games.
Before today, India's quickest to 150 Test scalps was EAS Prasanna. He took 34 matches to the milestone. The fastest in the world to 150 victims is England's Sydney Barnes, in 24 Tests.
Quickest to take 150 Test wickets (Top 5)
1. Sydney Barnes (England) - 24 matches
2. Waqar Younis (Pakistan) - 27
3. Clarrie Grimmett (Australia) - 28
4. R Ashwin (India), Hugh Tayfield (South Africa), Ian Botham (England), Dale Steyn (South Africa), Saeed Ajmal (Pakistan) - 29
5. Dennis Lillee, Shane Warne, Stuart MacGill (all 3 from Australia) - 31