The victory for the Scarlets marked only their fourth in 13 matches, while it was the Vodacom Bulls’ fifth defeat this season.
Scarlets got the better of the visitors from South Africa in the first half, scoring three tries to two, which handed them a handy 27-14 lead going into the sheds.
The second half was tight as both teams threw everything at one another, and this saw both sides earn their bonus point tries, although the hosts emerged victorious.
Scarlets flyhalf Sam Costelow earned the first points of the match compliments of a penalty goal in the third minute, but the visitors took the lead shortly after as Vodacom Bulls scrumhalf Zak Burger scored a smart try from a pick-go from a ruck to dash through.
The Scarlets applied intense pressure on attack and this paid off as they got over the tryline in the ninth with flank Dan Davis forcing his way through the defence to touch down.
The hosts’ prop Kemsley Mathias capitalised on some good forward play to score their second try in the 15th minute and they backed this up with their third try by scrumhalf Gareth Davies who gathered a great chip kick and dashed to the tryline five minutes. The successful conversions handed them an encouraging 24-7 lead.
The Pretoria side almost got over the tryline in the 23rd minute but the ball was held up and this was followed by an error-ridden spell by both teams.
The hosts extended their lead in the 31st minute with a penalty goal but they lost a man minutes later as Joe Roberts received a yellow card, and this paved the way for Vodacom Bulls wing Stravino Jacobs to dash through to the tryline in the 35th minute to reduce their deficit to 24-14 going into the break.
Costelow stretched their lead to 30-14 in the 45th minute, and the Bulls hit back strongly with back-to-back tries by flanker Cyle Brink and replacement prop Simphiwe Matanzima within seven minutes, which saw them earn their bonus point and trail by only two points.
The visitors were dealt a crucial blow in the 74th minute as wing received a yellow card for a late tackle, and fullback Johnny McNicholl made the most of this to add their bonus point try with two minutes left on the clock, which pushed the match out of range for the Pretoria outfit, and sealed the win for home side.
Scarlets 37 (27) - Tries: Dan Davis, Kemsley Mathias, Gareth Davies, Johnny McNicholl. Conversions: Sam Costelow (3), Dan Jones. Penalty goals: Costelow (3).
Vodacom Bulls 28 (14) - Tries: Zak Burger, Stravino Jacobs, Cyle Brink, Simphiwe Matanzima. Conversions: Chris Smith (4).