Sri Lankan legend Muttiah Muralitharan on Tuesday rated India's Ravichandran Ashwin as the best in the business among the current crop of off-spinners.Muralitharan, who holds the world record of 800 Test wickets, said the Indian is on top at the moment while also hailing Austrlian Nathan Lyon, who he feels bowls in different conditions."Ashwin, I think, is on the top at the moment as the best current Test spinner," Muralidaran was quoted as saying by Cricket Australia's (CA) website."Lyon is a very good bowler, a very good off-spinner. He has proven himself in Test cricket and has taken a lot of wickets for Australia. He bowls in different conditions (in Australia) which are not much helpful for spin but on the turning wickets he has taken some wickets."The 44-year-old, who had worked with the Australians as a consultant bowling coach in 2014, said the Kangaroos start as favourites when they take on Sri Lanka in the three-match Test series later this month."Australia is favourite at the moment because they have played good cricket in the recent past. Sri Lanka on other hand is struggling a bit in all forms of the game so Australia will have an edge over Sri Lanka," he said."They have a chance of winning the series because the Sri Lankan side is very inexperienced as lot of players retired recently and they are rebuilding the side so they won’t be strong enough.""Therefore, Australia I think will have a good chance of winning the series. If they use the conditions properly and play their spinners well they definitely have a chance."