It was a solitary strike two minutes into the second period courtesy of a superb lob from Thabo Rakhale to wrestle all three points from the hosts.The South Africans had to manage officiating which seemed to go against them with a clear-cut penalty waived away by the referee in the first half.
Orlando Pirates double their points to six, three points behind Egyptian outfit Zamalek.
In the 13th minute Lehlohonolo Majoro was left one-on-one with Sfaxien keeper Rami Jeridi, but his shot could not bypass the shot-stopper who deflected the ball out with a vital last touch.
On the quarter hour mark Thabo Matlaba made a bustling run into the box, and with three teammates waiting in the centre the fiery shotmaker blasted way off target instead of squaring for his forwards.
In the 27th minute, Pirates keeper Brighton Mhlongo pulled off a fine save diving low as Zied Derbali rifled in a well struck free kick from 25 metres out.
Pirates replied immediately with a good chance of their own. Majoro again made a swift entry into the Sfaxien box, but like his earlier attempt deposited his shot into the crowd.
Pirates were denied what appeared a clear cut penalty heading towards half-time. Sifiso Myeni made a menacing run goal-wards and was brought down in the six yard area in the 38th minute, but the referee waved away the strong penalty appeal of the Pirates players.
Just before the interval, Siyabonga Sangweni had a chance from an unmarked position in the box as he met a lofted corner, but his shot lacked any kind of direction and ended in a tame goal kick for the hosts.
In the 47th minute, Rakhale stole the ball off a Sfaxien player near the centre circle, put in a surge towards goal, and spotting the keeper off his line hit an audacious chip which went straight into the back of the net to forge a 1-0 lead for Pirates.
After their score, Pirates were content to sit back and let the hosts launch successive waves of attack. Though some times shaky on defence, Pirates were able to snuff out the danger on each occasion.
Substitute Kermit Erasmus, playing as a lone striker, had a rare chance for Pirates from a counter-attack to make it 2-0 in the 85th minute, but his shot from close range was straight at Jeridi.