The top side in the Premiership facing the leaders of the United Rugby Championship promised a mouth-watering match-up in Dublin.
Bath knew defeat would leave their qualification hopes out of their hands – and it was clear they were not willing to rely on results elsewhere to determine their fate.
Ted Hill’s rampaging run helped gain ground for Barbeary to power over, before De Glanville try further quietened the Dublin crowd after Finn Russell’s kick through had caused havoc in the Leinster defence.
Leinster have won every game this season and came into the game fresh off an away victory at La Rochelle.
The Irish province clicked into gear as Henshaw sharply finished two tries – the second assisted through sharp hands by New Zealand centre Jordie Barrett.
The four-time winners are known for blowing sides away in Dublin, but were left frustrated by Bath until captain Conan forced his way over to take the lead, with Obano in the sin-bin.
Despite being a player down, Ollie Lawrence produced a moment of magic to slice through the Leinster defence and set up De Glanville for his second and an unexpected lead at the break.
Leo Cullen’s side unloaded internationals Caelan Doris and Snyman from their bench early in the second half, which indicated just how well the visitors were smothering their attack.
A sublime Snyman offload helped gain territory for the South Africa lock to then stretch over and finish the score he started.
The replacements improved Leinster’s scrum, and two penalties and another yellow card for Obano followed.
The Premiership side would have had a tough task dealing with Leinster’s bench, containing eight internationals, with a full complement of players, and simply had too much to do following Obano’s dismissal.
Having been defeated late in the past three Champions Cup finals, Leinster will hope their new added depth will be the difference this year.
