"When you work hard, you are bound to get results and that's what we have achieved," said Jayawardene, who scored the fourth highest score of 374 in the first Test and a match-wining 123 in the second.
Jayawardene was relieved when Sri Lanka survived South Africa's dramatic fightback to record a tense one-wicket victory in the second and final Test at the Sara Oval here on Tuesday.
Sri Lanka, set 352 to win, lost three wickets for nine runs to slip to 350-9 after lunch on the fifth day before last man Lasith Malinga drove Nicky Boje for the winning run.
"It will take me some time to recover from this match," said Jayawardene. "It is one of the most exciting Tests I have played in and it showed how interesting Test cricket can be."
Sri Lanka, who were just 19 away from victory at lunch with four wickets in hand, were kept in the field for an hour after the resumption by the South Africans.
With 11 needed, Jayawardene stepped out to Boje and edged a catch to Herschelle Gibbs in the slips. Seamer Andrew Hall dismissed Chaminda Vaas and then clean-bowled Muttiah Muralitharan.
Maharoof levelled the score with a single off Boje before Malinga drove the next ball to the vacant mid-on region to seal a close win.
"I must confess I was a bit nervous when Murali got out, but both Maharoof and Malinga showed character and hung in there to get us to victory," the captain said.
"I had told the boys before the Test that South Africa would come back hard at us and they proved us right. But we stood up to the task well and deserved to win both matches."
The Sri Lankan captain hailed Muralitharan's 22 wickets in the two matches, saying the spin wizard showed why he is regarded by many as the best bowler in contemporary cricket.
"We were not surprised when Murali was named the man of the series. No one deserved it more," said Jayawardene.
"We in Sri Lanka rate him the best bowler in the game. The rest of the cricket world must also be thinking the same."
Muralitharan claimed 12 wickets in the Test to equal his own world record of four consecutive 10-wicket hauls. He had achieved the previous feat in the 2001-2002 season.
The off-spinner now has 657 Test wickets, second only behind Australian record-holder Shane Warne's 685.
South Africa's stand-in captain Ashwell Prince said he was proud of his team for fighting till the end.
"We never gave up and we knew that it would still be a match worth fighting for once we got Jayawardene out," said Prince, the first black cricketer to lead his country.
"Except for the first innings of the first Test when we got out for 169 we have matched the opposition in both batting and bowling.
"If only some catches had been taken, the result would have gone in our favour."
Prince said the absence of the injured duo of captain Graeme Smith and leading all-rounder Jacques Kallis for the series left his team depleted. Then pace spearhead Makhaya Ntini missed the final day's play due to a hamstring injury.
"Makhaya always makes a difference, it was a big blow not to have him when we needed him most," said Prince.
Sri Lanka and South Africa will now be joined by India for a limited-overs tri-series in Colombo from August 14-29.