Vodacom Bulls skipper and loose forward Marcell Coetzee opened the scoring very early on, while flyhalf Chris Smith added the extras for a 7-0 lead.
Jordan Hendrikse replied with a penalty goal shortly thereafter, with Smith doing the same to take the score to 10-3 in favour of the blue jerseys.
Just before the half hour mark, Cornal Hendricks went over in the right corner to round off a well-crafted team try which started with a clearance behind the Vodacom Bulls' goal line by new recruit Wandisile Simelane, playing against his former team mates.
The home side replied with a brilliant maul try from an attacking lineout which saw No 8 Francke Horn cross the line to narrow the deficit to 15-8.
Although the side from Pretoria deserved their half-time advantage, the Highvelders spilled some easy opportunities to put more points on the scoreboard. Hendrikse steered his conversion attempt just wide of the upright, while a more straight forward penalty attempt ballooned well wide.
It was the home side who made the made of a fast restart which saw hard-running inside centre Marius Louw crossing the line with a strong carry for a converted try to level the scores at 15-15.
However, their lead was very short-lived as Smith put the visitors back in the lead at 18-15 with an easy penalty goal, and he repeated the action later with two more successful strikes to take the advantage to 24-15 with 15 minutes of play still remaining.
The home side went into striking distance of the whitewash, but Sbu Nkosi prevented a certain try when he forced a turnover to take the thwart the attacking threat.
The Vodacom Bulls then added to their try tally when replacement hooker Jan-Hendrik Wessels was helped over the line for a maul try, which was converted by 38-year former Springbok flyhalf Morne Steyn to give the Pretoria outfit a commanding 31-15 lead which they defended until the end.
Scorers:
Emirates Lions 15 (8) - Tries: Francke Horn, Marius Louw. Conversion: Jordan Hendrikse. Penalty goal: Hendrikse.
Vodacom Bulls 31 (15) - Tries: Marcell Coetzee, Cornal Hendricks, Jan-Hendrik Wessels. Conversions: Chris Smith, Morne Steyn. Penalty goals: Smith (4).