The victory moves United to 22 points, just two behind pace-setters Sundowns, ahead of the Pretoria derby on Saturday
SuperSport United kept the pressure on Mamelodi Sundowns ahead of this weekend's Tshwane derby by recording a 2-1 league win over Bloemfontein Celtic at the Lucas Moripe Stadium on Wednesday evening.
Grobler's headed goal took him to 58 goals in total for SuperSport, overtaking the late Abram 'Fire' Raselemane as the club's all-time leading goalscorer.
Matsatsatsana had started the game well and were rewarded in the 13th minute when former Orlando Pirates striker Thamsanqa Gabuza netted from close range after a Sipho Mbule corner.
After Ronwen Williams made an important save for the hosts, Grobler squandered the chance to double their lead when he blazed a shot over the bar.
That came back to bite Kaitano Tembo's team shortly afterwards as SuperSport defender Grant Kekana gave away a penalty after taking down Ndumiso Mabena in the box.
After Mabena had been treated for an injury, Victor Letsoalo beat Williams from the spot to restore parity in the 23rd minute.
Boosted by the goal, more chances followed for Phunya Sele Sele - but Williams was up to the challenge as he saved from Siphelele Luthuli and Andile Fikizolo just before the half-hour mark.
At the other end, Grobler had a header saved by Jackson Mabokgwane in the 37th minute but got the better of the visiting keeper in the second minute of first-half added time as he nodded in another Mbule corner.
SuperSport went searching for a third goal after the restart as Ghampani Lungu made some dangerous runs down the wing, but he was unable to pick out Gabuza on the first occasion, while a later pass found the former Orlando Pirates striker, but the resultant volley was off-target.Having soaked up some pressure from Phunya Sele Sele, there was a 70th-minute opportunity for Mbule on the break, but he fired over the bar
At the other end, Harris Tchilimbou smashed a volley wide of goal in the 82nd minute, and although there were some anxious late moments for the Pretoria side, they managed to hold on for their fifth win in six matches. Celtic have now gone four league games without a win and sit just three points above the relegation zone.