In a six-try thumping at Welford Road, the visitors shone from start to finish, with Tommy Seymour, Mark Bennett and Jonny Gray all scoring in the first half.
That, coupled with a penalty try, gave the Warriors a bonus-point before 40 minutes was out, completing their emphatic display with Ryan Wilson and Tim Swinson tries.
Townsend’s Warriors enter new ground
More importantly, it kept Townsend’s side in Champions Cup contention, with a trip to Saracens or Guinness PRO12 rivals Munster to follow in the last eight – the side Warriors defeated on their way to the 2015 Guinness PRO12 title.
And the head coach felt the way his side handled themselves in Leicester mirrored that of their history-making day at the Kingspan Stadium two years ago.
WE'VE DONE IT! WE'RE THROUGH TO THE CHAMPIONS CUP QUARTER-FINALS FOR THE FIRST TIME!
— Glasgow Warriors ? (@GlasgowWarriors) January 21, 2017
“I know how important a day this is for us a club, but also for Scottish rugby,” Townsend said.
“This is a seminal weekend. It’d be great to build on this, in the next few weeks during the Six Nations, but also over the next few years.
“We’ve started something over the last couple of years. It started in Belfast and Dublin with the number of supporters that went over to watch us in PRO12 finals. This is how it starts.
“The noise they make, it’s not like they’re just any supporters. Scotstoun is a special atmosphere, today was so noisy.
“The PRO12 final, it’s hard to top that, but in many ways today reminded me of that day.”
— fraser brown (@fraserjmbrown) January 22, 2017
Munster defence holds firm to seal last-eight berth
Elsewhere in Pool 1, Munster ensured themselves a home tie in the quarter-finals by beating Racing 92 22-10 at Thomond Park.
Simon Zebo ended a quiet first half with the game’s first score, while Ronan O’Mahony and Ian Keatley also dotted down and Tyler Bleyendaal added seven points from the boot.
— Munster Rugby (@Munsterrugby) January 22, 2017
And while Henry Chavancy crossed for Racing, the Champions Cup’s best defensive side kept up their run, conceding just four tries in their five pool matches.
However, both Scarlets and Ulster played their last games of the competition, downed by Sale Sharks and Bordeaux Begles respectively.
Ospreys hit perfect 30, but Tandy’s after more
History was made in the European Rugby Challenge Cup as Ospreys became the first side to register a perfect 30 points in pool-stage competition as Scott Otten’s late score sealed the bonus-point 26-21 victory over Newcastle Falcons.
For a time it seemed the accolade would elude the Welsh region, with Rhys Webb’s fifth-minute score the only try in 55 minutes as the hosts roared into a 21-7 lead.
But Ospreys battled hard, with Hanno Dirksen and Sam Davies getting tries prior to Otten’s score ten minutes from time, sealing the turnaround and a home quarter-final to boot.
Tonight's BP win means we are the first team in European history (in either competition) to register the maximum 30 points in the pool stage
— Ospreys (@ospreys) January 21, 2017
“It won’t count for a lot when it comes to the quarter-finals,” said head coach Steve Tandy.
“For the group as a whole, it’s been a good stage for all of us. It’s a record and it’s never been done before but it means nothing now.
“But we go into the last eight which is really pleasing for the squad.
“The first half’s probably the worst half we’ve played in the competition but how the boys battled back was really pleasing.”
No Blues for Cardiff in bonus-point success
They’ll be joined in the last eight by Cardiff Blues, whose 22 Pool 4 points proved enough to earn a best runner-up spot and an away last-eight berth.
A double salvo from Kristian Dacey and Gareth Anscombe sent Danny Wilson’s men on their way against Bristol Rugby, with a Matthew Morgan brace and Sam Warburton’s late score securing the bonus point and a 37-21 win.
— Cardiff Blues (@cardiff_blues) January 22, 2017
Newport Gwent Dragons have played their last Challenge Cup game of the season though, with Sarel Pretorious’ double not enough to prevent a 36-19 defeat to Pool 3 winners Brive.
Saturday also saw the end of the road for Benetton Treviso, but not without causing La Rochelle an almighty scare in France.
Edoardo Gori’s try had his side 8-0 up at the break, but four unopposed tries saw the hosts battle to a 31-8 victory, now set to face Edinburgh in the last eight.
Guinness PRO12 Final 2017, 27th May, Aviva Stadium, Dublin.
Ticket Information: Fans can still avail of an exclusive number of €30 tickets. Book via www.ticketmaster.ie.
Further information: www.pro12rugby.com/final