Sri Lankan batsman Hashan Tillekeratne is enjoying the best form of his career after fighting his way back into the team after two years out of favour with the selectors.

Tillekeratne collected his 10th Test century at Centurion Park - the first by a Sri Lankan against South Africa - and is hoping there are more to come despite being 35 years of age.

He was dropped following the 1999 World Cup in England and had to wait until August last year for another chance.

"I was shocked. I never thought I'd get dropped from the Test squad," the left-hander commented.

"I lost two good years - I have a lot of catching up to do."

Tillekeratne went into the game at Centurion having averaged 78 since his return against India last year.

He has assumed greater responsibility in the middle order following Aravinda de Silva's decision to retire from Test cricket.

And he was determined to make South Africa work harder than they had to in the first Test, which they won inside three days by an innings and 64 runs.

"It's always nice to get a hundred against the mighty South Africans.

"We really had a bad run at The Wanderers, so we wanted to eliminate the mistakes we made there."