Mendis made his debut for Sri Lanka in 1972, batting at number three against the visiting Tamil Nadu side.
He was hit in the head by Jeff Thomson in a match versus Australia, and when able to speak again, told the Australians "I am going now", retiring hurt on 32.
[2] It took seven more years before Mendis got to play a Test match; on 17 February 1982 he joined forces with the other Sri Lankans against England.
Again, the openers fell for single-digit scores, and again Mendis made 105 – which helped Sri Lanka bat until tea on the fifth day.
Mendis recorded a string of poor scores on New Zealand's tour of the island in 1984, only passing 20 once in six Test innings.
A poor World Series Cup in 1984–85 followed, where Sri Lanka only won one out of ten ODIs, and Mendis was out in single figures four times.
Ranjan Madugalle replaced him as captain for the last Test that Mendis played, where he bowed out with a rearguard 56 that was, however, not to be good enough to save a draw.