The visiting side went into the halftime break firmly in command with the score 20-7 in their favour at Emirates Airline Park, and the win pushed them to the top of the Carling Currie Cup standings.
It was a determined Sigma Lions outfit that came roaring back in the second half, scoring four tries to deliver a much improved performance after the break. In the end, they matched the Cell C Sharks' overall tally of five tries, however, the difference was their tendency to concede penalties at regular intervals, which allowed Boeta Chamberlain and Sanele Nohamba to kick four successful penalty goals, which ultimately proved the difference.
The Sigma Lions got the match off to a perfect start when right wing Boldwin Hansen exploited a lapse in the Cell C Sharks' defence to snatch a high bouncing ball away from Yaw Penxe, turning on the speed dial to score under the posts. Vaughen Iaacs added the extras to give them a 7-0 lead.
But the Joburg side themselves then had a soft moment which allowed hard-running Cell C Sharks left wing Marnus Potgieter to cut inside and beating the cover defence for the visitors' quick response. Chamberlain slotted the conversion from a difficult angle to level the scores at 7-7 and with a lot of rugby still to be played in the first half.
Unfortunately for the Jozi side, Hansen had to leave the field halfway through the opening stanza due to a leg injury and he was replaced by the experienced Fred Zeilinga.
Meanwhile, Cameron Wright, who was named Man of the Match, exploited the home side's brittle defence once more when he was allowed to break from the back of a solid scrum to score out wide for another converted try. Apart from the conversion, Chamberlain also added two penalty goals to stretch the visitors' halfway lead to 13 points.
The home side's lineout was also a cause for concern as they allowed their opposing jumpers to spoil many throw-ins, thereby depriving them from a good attacking platform.
The KwaZulu-Natalians quickly got into their stride after the restart, scoring further tries through loose forwards Thembelani Bholi and Mpilo Gumede as well as replacement hooker Dan Jooste. The Highvelders were not to be outdone as they managed to cross the whitewash on four occasions.
Loose forward Emmanuel Tshituka went over the line from close while left wing Divan Rossouw made the most of Vincent Tshituka's power surge to dot down near the corner. Later on Morne Brandon and James Mollentze also helped themselves five pointers.
Three Cell C Sharks players were shown yellow cards for two dangerous tackles and a cynical foul, namely Wright, Bradley Davids and OJ Noa.
Sigma Lions 31 (7) - Tries: Boldwin Hansen, Emmanuel Tshituka, Divan Rossouw, Morne Brandon, James Mollentze. Conversions: Vaughen Iaacs (3).
Cell C Sharks 45 (20) - Tries: Marnus Potgieter, Cameron Wright, Thembelani Bholi, Mpilo Gumede, Dan Jooste. Conversions: Boeta Chamberlain (3), Sanele Nohamba. Penalty goals: Chamberlain (2), Nohamba (2).