And it was eventual champions Racing 92 blocking the path in last year's group stage, and despite the pre-match boost of Stuart Hogg signing a contract extension, Townsend is expecting a tough test at the hands of one of English rugby's elite.
"The European Rugby Champions Cup is a brilliant tournament to be involved in and an opportunity for us to play the best teams in Europe," said Townsend.
"Leicester have been one of Europe's leading sides for a number of years and we know they'll provide a tough test on Friday night.
"But there is a lot of excitement within our squad and we're looking forward to opening our campaign at home in front of a sold out Scotstoun."
Guinness PRO12 sides are also in Challenge Cup action, with head coach Steve Tandy feeling it is imperative Ospreys get off to a fast start in their campaign - starting with Friday night's clash with Newcastle Falcons.
Ospreys have been forced to step down from last season's Champions Cup campaign where they were eliminated from the pool stage - despite finishing with the same number of wins as all other group members.
But with tricky trips to Lyon and Grenoble following Friday's game at the Liberty Stadium, Tandy knows the significance of replicating last season's European form by winning all games on home territory, and is backing the region's fans to help them out.
"It's crucial that we start the campaign positively. Newcastle have done well so far this season in the Aviva Premiership and are up in the top half of the table so they'll be confident coming to the Liberty," he said.
"We know that out supporters will do their bit on Friday night as they always do. That's big for us, they can play their part in pushing us on when the going gets tough, as it will.
"With a couple of trips to France to follow, it's important that we get our performance right and that's been a key message this week in training."
The Falcons have made 13 changes for the game, while Alun Wyn Jones starts for Tandy's side as does fellow Lion Dan Lydiate for the first time this season.
Ospreys got the better of Cardiff Blues in the Guinness PRO12 last week, a side also in Challenge Cup action this weekend - with Rey Lee-Lo relishing coming up against familiar faces in the form of Premiership side Bristol Rugby.
The Samoan centre has a number of strong relationships with the English side, with David Lemi, Jack Lam, Anthony Perenise and Tusi Pisi in their squad.
And with Bath Rugby and Pau also set to face the side knocked out in last year's pool stages, Lee-Lo knows the Blues need to fight back sooner rather than later if they are to reach the knockout stages.
"I have a few mates over there (in Bristol)," he said. "I watched their game last week against Newcastle and while they lost they were really good in the second-half and they will bring that same intensity. We have to man up and stop them.
"We have taken the learnings from the Ospreys game but otherwise it's back to normal, it's another week and we can't look back, our focus is on Bristol."
While the Blues have not had the best record in Europe, Newport Gwent Dragons are a side looking to maintain theirs when they host CA Brive on Friday evening - a side they scored six tries against in their previous meeting in 2007.
The men of Gwent made the Challenge Cup semi-finals last season, fighting back before slipping to eventual-winners Montpellier 29-16. Bath Rugby and Pau make up the rest of their pool.
Guinness PRO12 Final 2017 Ticket Information: Fans can save up to 20% on selected tickets, and prices start at just €30 adults and €5 child, and be booked via www.ticketmaster.ie. For further information visit http://www.pro12rugby.com/final
Guinness PRO12 Ospreys News
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