The visitors were good value for their win scoring seven tries to the Valke's four.They built up a 14-0 lead within the first half an hour with No 8 Muller Uys scoring both tries. Fylhalf Marnitz Boshoff kicked the conversions.
The Valke narrowed gap as centre Juandre Nel sped over for scrumhalf Andre du Plessis to convert.
The Pretoria team made it a 14-point game again minutes later as centre Wian van Niekerk forced his way over. Boshoff added the extra two points but the Valke had the last say of the half as flank Thabo Mabuza scored the first of his two tries.
The Vodacom Blue Bulls enjoyed a successful period after the restart scoring tries through flank Roelof Smit and fullback Duncan Matthews (2). Boshoff slotted two of the conversions to make it 40-12 with 23 minutes to play.
Valke lock Shane Kirkwood and Mabuza then crossed the tryline for the home team but Llewellyn Claasen closed off the game for the visiting team's seventh try.
Valke - Tries: Shane Kirkwood, Thabo Mabuza (2), Juandre Nel. Conversion: Andre du Plessis.
Vodacom Blue Bulls - Tries: Roelof Smit, Muller Uys (2), Wian van Niekerk, Duncan Matthews (2), Llewellyn Classen. Conversions: Marnitz Boshoff (5), Fiela Boshoff.