The hosts declared their second innings to set a huge victory target of 490 and they are on the verge of a crushing success after spinners Akila Dananjaya and Rangana Herath each took two wickets to reduce South Africa to 139 for five.
Theunis De Bruyn was the only South Africa batsman to offer any resistance with an unbeaten 45 off 97 balls. He remains at the crease with Temba Bavuma (14).
Dimuth Karunaratne (85), Danushka Gunathilaka (61) and Angelo Mathews (71) all posted half-centuries as Sri Lanka declared on 275 for five after starting the third morning on 151 for three.
For South Africa, who must win the second Test to avoid defeat in the two-match series, left-arm spinner Keshav Maharaj took three for 154 to finish with a 12-wicket match haul.
Sri Lanka won the opening Test in Galle by 278 runs inside three days and another comfortable victory looks on the cards.
Stuart Broad makes his return from injury as Nottinghamshire host leaders Surrey in the County Championship.
The experienced seamer, who injured his ankle playing for his county last month, will expect to have his feet up for most of the first day after second-placed Notts were put in to bat at Trent Bridge.
James Anderson, Jos Buttler and Keaton Jeanings’ battle with England team-mates Joe Root and Jonny Bairstow will have to wait after rain at Old Trafford delayed the start of Lancashire’s match against Yorkshire.
Moeen Ali will have the first chance to impress in his showdown with fellow spinner Jack Leach after Worcestershire opted to bowl in their Division One clash with Somerset, who were without Dom Bess – England’s slow bowler in the series against Pakistan.
In Division Two, Dawid Malan – England’s incumbent number four – won the toss as Middlesex captain and chose to bat against Warwickshire, boosted by the availability of all-rounder Chris Woakes.
Durham pair Mark Wood and Ben Stokes will have the ball in their hands early after Gloucestershire won the toss and batted in their game at Cheltenham.
MS Dhoni’s recent form has been in the spotlight after India’s 2-1 defeat to England in the ODI series. The veteran wicketkeeper-batsman’s display generated strong criticism from former players and his decision to collect the match-ball from the umpire after the deciding ODI at Headingley had sparked speculation about a possible retirement.
However, Dhoni’s former team-mate and India legend Sachin Tendulkar has said that the Ranchi-born man would be the best-placed to take a call on his retirement.
“I know people are talking about a lot of things… I have read Mr (Sunil) Gavaskar’s statement and seen Sourav’s (Ganguly) remark that Dhoni needs to do more. But if you speak to MS himself, he would also say that it has not been up to his expectations,” Tendulkar told the Mumbai Mirror in an interview.
“The player only has to take the call. A player of his calibre, who has been around for a long time, knows what is expected of him. And where he stands. So, I will leave the decision to him,” he continued.
Dhoni was booed by some sections of the crowd at Lord’s in the second ODI at Lord’s during his painstakingly slow knock of 42 in 69 balls as India went on to lose the match.
Virat Kohli’s men will now lock horns with the hosts in a five-match Test series that gets underway at Edgbaston on August 1. Tendulkar believes respecting the conditions will be the key for the visitors.
“The first basic rule (of an overseas tour): Respect conditions. It’s the key. The first morning of the series, the first over, the first spell – it’s always the key. It was the same in South Africa, it will be the same in England,” he added.