Eastern Province qualified for the semi-finals of the Absa First Division when they beat Border 57-36 in East London on Friday night.
The Elephants outscored the Bulldogs by eight tries to five, with right wing Norman Nelson grabbing a hat-trick.
EP were ahead 15-3 after just eight minutes but a try by Bulldogs flanker Lubabalo Mzwakali triggered by a run from left wing Luvuyo Sogidashe sparked a shortlived Bulldogs comeback.
A converted Stephan Britz try had the Bulldogs 17-15 ahead but the Elephants then hit back through a Chris Jonck penalty and an Elroy Ligman try with another coming from lock Luke Belling for the Elephants to lead 28-24 at the break.
The Elephants were ahead just 40-36 with 20 minutes to go, before Noel de Villiers scored to take the game away from the hosts.
Bulldogs - Tries: Lubabalo Mzwakali, Stephan Britz, Michael Coetzee, Pietie Loots (2). Conversions: Reinhard Gerber (4). Penalty: Gerber.
Elephants - Tries: Michael Killian, Baldwin McBean, Elroy Ligman, Luke Belling, Noel de Villiers and Norman Nelson (3). Conversions: Chris Jonck (4). Penalties: Jonck (3).