Both of them made it five out of five when Toulouse trounced Newport 70-18 in Pool 5 and Leinster romped to a 48-19 victory over Swansea in Pool 4.
Toulouse now travel to London Irish and Leinster to Bristol Shoguns for Sunday showdowns in which wins No 6 would ensure them the golden rewards of the top two seeding places and home advantage against the two best runners-up, the seventh and eighth seeds, in April's quarter-finals.
In the past seven years only six teams have made clean sweeps of their group stage matches ... but only two of them have gone on to lift the trophy. Toulouse went all the way in 1996 and Brive matched them a year later.
However, Leinster (1996), Leicester (1997), Wasps (1998) and Bath Rugby (2002) all found the knock-out stages different stories after sailing through their groups.
In 1995-96, the first season of the tournament when teams only played two Pool games, Toulouse and Leinster both went through to the semi-finals with 100 per cent records.
A year later and, with the arrival of English and Scottish teams, there were four Pool matches each, with Leicester and Brive stringing together six straight wins en route to an epic final.
However, since 1997 and the introduction of six group fixtures for all competing sides, only two clubs have managed that perfect Pool record - Wasps in 1997-98 and Bath Rugby last season. Neither survived past the quarter-finals.
Wasps went down 25-18 to Brive and Bath were sunk 27-10 by Llanelli, despite both having home advantage in the last eight.