Exeter Chiefs head coach Rob Baxter believes is evidence of the on-field progress made at Sandy Park.
Baxter's side, enjoying a first taste of Europe's major cup this term, won 22-16 to record their first success.
"We've won a Heineken Cup game in a pressurised environment at a tough place," Baxter told BBC Radio Devon.
"The players should feel immensely proud. It's a landmark and it shows we've taken another step forward."
The Chiefs' development as a Premiership outfit, in addition to their European commitments, has been notable in their third season post-promotion.
England recognition for Tom Johnson and Haydn Thomas has shed the spotlight on Exeter's squad, which has been tested by top-level competition.
Meanwhile one player hoping to catch the eye of the Ireland selectors is fly-half Gareth Steenson, whose kicking was pivotal to victory at Parc y Scarlets.
The 28-year-old contributed 17 points with unerring place kicking accuracy, while Thomas scored his first try in the tournament.
"Ultimately I don't think he missed [a kick]," Baxter continued.
"If your goal kicker keeps knocking them over like that and you can create some pressure situations, it's amazing how quickly you can build a score.
"The guys took some good decisions about how we built that score and how we created some platforms and ultimately that is what has won us the game."