The loss marked back-to-back defeats for the side and bumped them out of the top three on the standings in Conference A.
The first half proved to be tight as both sides ran hard on attack and backed this up with solid defence, which saw only one try being scored compliments of Ulster replacement prop Tom O'Toole.
The second half was equally competitive, with each side only being able to score a converted try.
The Free Staters, however, will be rueing missed opportunities as unforced errors close to the tryline on a handful of occasions cost them dearly.
Toole opened up the scoring in the ninth minute, forcing his way over the chalk with a strong pick-and-go after some good pressure by the team, and the successful conversion pushed them 7-0 ahead.
The Toyota Cheetahs fought back with intent, and they camped close to the tryline for several minutes, but they were unable to breach the tenacious defence.
Ulster’s Bill Johnston (flyhalf) stretched the hosts’ lead to 10-0 in the 36th minute with a penalty goal, but this was cancelled out by Toyota Cheetahs captain and scrumhalf, Ruan Pienaar – a former Ulster star – who slotted a three-pointer for the visitors to see them enter the break 10-3 down.
The Free Staters found themselves under pressure early in the second half as Wilmar Arnoldi (hooker) received a yellow card for collapsing a maul, and the home side capitalised on this with Robert Baloucoune (winger) scoring in the corner after gathering a pin-point chip kick.
Johnston added his second penalty goal going into the fourth quarter, which nudged the hosts into a 20-3 lead. But the Toyota Cheetahs hit back with a try by Clayton Blommetjies (fullback) who finished off a fantastic run of play following a valuable intercept.
Neither team was able to add to their score in the closing minutes, which saw Ulster seal the 20-10 win.
Ulster 20 (10) – Tries: Tom O'Toole, Robert Baloucoune. Conversions: Bill Johnston (2). Penalty Goals: Johnston (2).
Toyota Cheetahs 10 (3) – Try: Clayton Blommetjies. Conversion: Ruan Pienaar. Penalty Goal: Pienaar.