The Joburg outfit led 20-14 at halftime but the Cheetahs turned things around in the second half to make it eight wins from eight games, whilst the Highvelders slumped to their ninth loss in a row.
They outscored the Highvelders by four tries to two as they registered another deserved bonus-point win on the road.
Ruan Pienaar, their inspirational skipper and scrumhalf, led from the front as the Free Staters had to fight back on more than one occasion to eventually down a spirited Lions team who were desperate for their first win of the campaign.
Tiaan Swanepoel, the Sigma Lions fullback, succeeded with six from eight goal kicks attempts for a personal tally of 16 points, while Pienaar managed to kick three penalties and three conversions in his contribution of 15 points to their winning cause.
After they withstood a fiece opening spell from the Free Staters – during which time the visitor had two tries disallowed - the home side went into the halftime break 20-14 in front. The difference between the two teams was the two Swanepoel penalties.
The Toyota Cheetahs scored both their first half tries through mauls. No 6 flank Gideon van der Merwe grabbed their first five pointer while hooker Marnus van der Merwe dotted down for their second converted try from a similar passage of play to edge them 14-13 ahead.
Stean Pienaar (wing) and Lindo Ncusane (flank) each dotted down for the white and red jerseys, while Swanepoel added the extras via two conversions and a couple of penalty goals.
Sanele Nohamba, the Sigma Lions’ newest signing from the Cell C Sharks, made his debut off the bench for his new team halfway through the first half when he replaced skipper Andre Warner. That was before Swanepoel had landed two more penalty kicks to put his side 26-17 ahead.
Cheetahs left wing Duncan Saal dived over in the corner as the orange jerseys made sure they stay in the fight with their third try of the evening which Pienaar brilliantly converted from the edge of the touchline.
When Pienaar slotted his second penalty kick of the evening it was the team from Bloemfontein who regained the lead at 27-26 with eleven minutes remaining on the clock.
That try signalled the huge momentum in favour of the visitors, who added a fourth try through replacement hooker Louis van der Merwe for their vital bonus point.
In doing so, Hawies Fourie’s team regained the top spot on the log with 36 points from their eight wins, leaping over the Vodacom Bulls who have 32 points from the same number of games.
The defending champions host the Windhoek Draught Griquas tomorrow afternoon at Loftus in Pretoria.
Sigma Lions 26 (20) - Tries: Stean Pienaar, Lindo Ncusane. Conversions: Tiaan Swanepoel (2). Penalty goals: Swanepoel (4).
Toyota Cheetahs 35 (14) - Tries: Gideon van der Merwe, Marnus van der Merwe, Duncan Saal, Louis van der Westhuizen. Conversions: Ruan Pienaar (3). Penalty goals: Pienaar (3).