Smith faces new left-arm nemesis

Who will emerge as the No. 1 from the No.1s? And will the forceful fast-bowler tame one of the most belligerent batsmen of them all? South Africa and Sri Lanka play too infrequently for patterns to have formed but, with the two relative strangers meeting for the first time in five years, the stage is set for some new contests to find their place in cricket folklore. ESPNcricinfo picks out some of the key battles to look forward to in the upcoming series.

Welegedara v Smith
First it was Mitchell Johnson, then Zaheer Khan and now it could be Chanaka Welegedara, who will pose problems for the South African captain. Graeme Smith has, over the past three seasons, been unable to adjust to the angles from the left-hander and unless he has made significant technical adjustments to his game, Welegedara could be his next nemesis. Although Welegedara has only played in 14 Tests, he is the second most experienced bowler in the Sri Lankan attack and if he can pluck the opposition captain early, it will go a long to easing the burden on his countrymen as the innings unfolds.

Steyn v Sangakkara
This duel is as high-end as it gets with both Dale Steyn and Kumar Sangakkara at the very top of their respective rankings. Both have come off successful patches, with Sangakkara scoring a double-hundred and a century in Sri Lanka's series against Pakistan and Steyn snatching 11 wickets in the two Tests against Australia. Sangakkara is a notably accomplished player of fast bowling while Steyn will be plying his trade on some of his favourite pitches, surfaces on which he has enjoyed success before. Sangakkara's strokeplay cannot get more sublime, Steyn's swing could not be more dangerous and when the two meet, a clash of the Titans is expected.

Tahir v the Tail
South Africa have long lamented their inability to dismiss lower-orders quickly, painlessly and efficiently and Imran Tahir has showed signs that he has the ability to change that. In four overs against Australia at the Wanderers, he finished off their tail and that has been identified as one of the most important aspects of his role going forward. Sri Lanka have not been exposed to too much legspin of late and if there were two players that would be vulnerable against it, the likeliest place for them to bat will be in the tail. With pitches expected to be seamer-friendly, Tahir may have to wait for days four and five in order to be effective but he proved to be what South Africa need to convert nail biting draws into thrilling wins.

Herath v Amla and Kallis
Spin is rarely talked about as a key factor in a Test series in South Africa, but this time may be different. Sri Lanka have been dealt several blows in the pace department and could rely on Herath to play a duel attacking and containing role, similar to the one he did during the tour match in Benoni. His ability to make the ball grip and turn will make him a danger factor and the two batsmen who could deal with him best in South Africa are Hashim Amla and Jacques Kallis, who both play spin as though they were born doing it. Amla's wristy approach and Kallis' fluent footwork could see them either dictate passages of play against him or if Herath wins the contest and the pair fall victim to him, swing momentum Sri Lanka's way.

Philander v Dilshan
Vernon Philander rewrote impressions of himself when arrived to play Australia as a wily, aggressive, fast-bowler, a completely different person to the cocky youngster who bombed out of the national team five years ago. Although not lightening quick, Philander varies his lengths well and maintains a constant "fourth stump" line outside off. He is constantly on the attack which will make for an interesting contest when he comes up against Dilshan, who is exactly the same. Having already confessed to enjoying "scoring runs on bouncy tracks," green tinges, patches of grass, or even entire pitches are not going to scare the Sri Lankan captain. Mahela Jayawardene said one of the best ways for Sri Lanka to be competitive in this series is to play their normal brand of cricket, which is flamboyant strokemaking. Dilshan will not have to be told twice.

Boucher v himself
With twilight on the verge of becoming night for Mark Boucher, this series could decide if his career will continue. Boucher's underperformance with the bat against Australia raised eyebrows and started calls for a suitable replacement to be found and groomed. So far, no stand-out candidate has emerged, giving Boucher the opportunity to prolong his time as an international cricketer if he can produce runs for the lower-order. Despite a half-century against India in Cape Town in January, Boucher's average of 30.29 has come under scrutiny, especially since South Africa carry a longer tail than they did in the past. An innings that shows his character and big-match temperament will go a long way to booking his flight on South Africa's upcoming tours but getting out cheaply and selecting shots poorly will likely mean Boucher can start preparing for life after cricket.