The Pretoria team conceded a red card, two yellow cards and a penalty try on way to a remarkable win over the home side, who came into this round five match undefeated.
The visitors refused to stop playing and it was their enterprise in attack that gave them the edge, although the gutsy defensive effort probably won them the match, their first win at this venue in seven years.
On attack, Vodacom Blue Bulls, Manie Libbok, had no peers.
The young pivot set up an early try to Cornal Hendricks and a couple of minutes later ran the telling line that saw Dayan van der Westhuizen scoring his side's second unanswered try.
The Vodacom Blue Bulls started like a team on fire, with Libbok's angled run putting Hendricks away to score within the opening 30 seconds.
Van der Westhuizen's try extended the Pretoria team’s golden start, as he took a final pass from Libbok in a move that started when the home side spilled an up-and-under.
The blue wave turned red though after 17 minutes when debutant flanker, Fred Eksteen, was shown red for foul play.
The home side sniffed a weakness in the arsenal of their Pretoria foes and used their extra numbers to force a penalty try via a strong scrum.
Home flyhalf, Shaun Reynolds then exploited the lack of defence on the side of a scrum from a put-in near the Vodacom Blue Bulls line, but missed the conversion to leave the sides at 12-all.
The Vodacom Blue Bulls refused to stop playing though and their endeavours in attack, with midfielder Dylan Sage pretty industrious, forced the defence lines of the home side to go offside.
Libbok kicked two penalties to edge his side to a 18-12 lead, but missed a long range effort to extend that lead going into halftime.
The second half again saw the Pretoria side starting with more purpose.
Libbok set up Van der Westhuizen again, but the prop was ruled short on the touch down. From the resulting scrum, Libbok took matters in his own hands to touch down and convert.
Trailing 12-25, the Xerox Golden Lions started their comeback.
Hooker Pieter Jansen scored off a solid driving maul, with Reynolds converting.
Libbok kicked his third penalty to take the lead out to nine points again, but a yellow card for lock Andries Ferreira left the visitors with 13 men on the field.
They held out for seven minutes, but winger Stean Pienaar scored a good team try, with the Reynolds conversion making it a two point game (28-26).
Libbok kicked a long range effort from close to 50 meters to make it a five-point lead again and with the home side attacking from all angles, some brave defence kept that intact.
Sage was yellow carded in the last frantic minutes as well, but the home side were unable to produce the final effort to deny the Vodacom Blue Bulls a remarkable win.
Xerox Golden Lions 26 (12), Vodacom Blue Bulls 31 (18)
Xerox Golden Lions - Tries: Shaun Reynolds, Stean Pienaar, Pieter Jansen, Penalty Try. Conversions: Reynolds (3).
Vodacom Blue Bulls - Tries: Cornal Hendricks, Dayan van der Westhuizen, Manie Libbok. Conversions: Manie Libbok (2). Penalties: Libbok (4).