There were more fireworks outside the ground than in it as these Pool Two hopefuls slugged it out at an echoing Lansdowne Road. Victory came at a price for Leinster and Ireland, though, with the loss to injury of the centre Gordon D'Arcy.
He damaged his groin when scoring Leinster's third try and may mean he misses the start of the autumn internationals.
That Leinster secured victory owed as much their solid defence as it did to Bath's singular inability to turn promising positions into points.
The English club also lacked a solid defence of their own. Having found it impossible to play Olly Barkley anywhere but at fly-half, the Bath management's preferred choice for that position, Chris Malone, had found himself of late playing at full-back - and out of his depth.
Certainly that is how it looked as first Denis Hickie and then Shane Horgan in each half got past him with ease for two of Leinster's three tries. The home side could have done with another touchdown because Treviso's shock victory over the French side Bourgoin on Friday night had added a sense of urgency to this fixture, where the accumulation of try-scoring bonus points has now become paramount.
The first half had been blown into a thousand fragments by the referee Nigel Williams's whistle-stop approach, but all either side had to show for the 16 penalties which interrupted proceedings in that first period was a goal-kick apiece.
Bath's attack had been shorn of the services of their powerful left wing Brendan Daniel after a late fitness test on a dead leg hours before the kick-off. Worse was to come, as some 19 minutes after the game got underway, Robbie Fleck, their muscular Springbok centre, left the field with an injured left leg.
Leinster's backs comprised Ireland's test three-quarters and full-back and their class was apparent from early on when Brian O'Driscoll and D'Arcy punched holes in the Bath cover.
On one occasion O'Driscoll looked to have cleared the way with a sudden spurt through, but if his pace was electric, his final pass to Horgan was shocking, although there was nothing wrong with his delivery a little later, when he collected the fly-half Shane Holwell's astute pass and sent Hickie over in the corner for his 14th try in the competition.
Bath's response was instant, with something of an Alamo moment which saw Spencer Davey feeding Alex Crockett, who was scorching up the left.
Bath began the second half well and Tindall, watched by the British and Irish Lions head coach Sir Clive Woodward, was an ever-present threat to the Leinster line.
So there was all-round relief when D'Arcy thumped over a long-range drop goal and followed that up by cancelling out a second Bath penalty with another of his own.
Then Leinster pretty well sealed it with a fine try by D'Arcy that saw him diving over on the left having brushed aside the attention of Malone. However, the referee still needed confirmation by video.
But the cheers when the try was awarded were stilled immediately when it became apparent that D'Arcy had been injured while performing his heroics. At least Leinster go into the short European break leading the pool.
Leinster: G Dempsey; S Horgan, B O'Driscoll, G D'Arcy (G Brown, 67), D Hickie; D Holwell, B O'Meara (G Easterby, 80); R Corrigan (capt), S Byrne, E Byrne (R Nebbett, 40), M O'Kelly, L Cullen, E Miller, V Costello (A McCullen, 71)), S Jennings.
Bath: C Malone; A Higgins, R Fleck (S Davey, 19 (N Walshe, 39-40)), M Tindall, A Crockett; O Barkley, M Wood (N Walshe, 71); D Barnes, J Humphreys (capt; L Mears, 23-32 & 59), D Bell (M Stevens, 38), S Borthwick, D Grewcock (R Fidler, 65), A Beattie, I Feaunati (G Delve, 71), M Lipman (J Scaysbrook, 77).
Referee: N Williams (Wales).