In their final warm-up game ahead of next Friday’s Guinness Pro12 opener against Treviso, Leinster were facing into an early 13-point deficit, courtesy of eight points from the boot of Rhys Priestland and a 5th-minute try by lock Dave Attwood.
The Blues finally opened their account on 16 minutes with a well-worked five-pointer from Adam Byrne, and this was swiftly followed by a converted Ross Molony try from the subsequent attack.
However, it was Bath who had the final say in the opening period, with Jeff Williams diving over in the right-corner to help the visitors to establish a 20-12 interval cushion.
In a similar vein to their two previous encounters, Leinster made wholesale changes for the start of the second-half, but just past the hour mark, they found themselves falling further behind.
An audacious off-load by Bath replacement Dave Sisi left winger Rokoduguni with the simple task of touching down on the right-wing. This left Leinster with a mountain to climb in the final-quarter, and even though superb approach work by Rory O’Loughlin resulted in a 72nd-minute try for Barry Daly, Bath sealed their win with subsequent breakaway five-pointers from Davies and Ford.
A Byrne, R Molony, B Daly try each, J Carbery, R Byrne con each.
D Attwood, J Williams, S Rokoduguni, H Davies try each, R Priestland 2 pens, 2 cons, G Ford try, 2 cons.
R Kearney; G Ringrose, R O’Loughlin, N Reid, A Byrne; J Carbery, J Gibson-Park; C Healy, J Tracy, M Bent; R Molony, M McCarthy; J Murphy, D Leavy, P Timmins.
B Byrne, A Porter, J Loughman, H Triggs, D Ryan, N McCarthy, C Marsh, Z Kirchner, S McNulty, P Dooley, I Nagle, J van der Flier, C Rock, R Byrne, T Daly, B Daly.
A Watson; J Williams, M Clark, D Bowden, S Rokoduguni; R Priestland, K Fotuali’i; N Auterac, R Batty, H Thomas; D Attwood, L Charteris; M Garvey, D Denton, T Faletau.
T Dunn, N Catt, K Palma-Newport, C Ewels, T Ellis, D Sisi, W Homer, G Ford, R Jennings, H Davies. George Ford
F Murphy (IRFU).