Srilanka has always been especially formidable at home. The only two teams to beat Srilanka in Srilanka since 2001 are Australia and Pakistan.
India lost 2-1 in 2008 and has actually lost its last two series in Srilanka. One in 2008, less than a year ago and one before that in 2001.
Results | Global | Cricinfo.com
Results | Global | Cricinfo.com
After mentioning that “recent” series (less than 12 months ago), which incidentally happened right after India 20/20 triumph, I do recall Srilankas first test victory which was against India right after the mini world cup which India won in 85, and the WC in 83. That was also Srilankas first series win.