Holders Exeter went out of the European Champions Cup after sliding to a 34-22 defeat at home to four-time champions Leinster on Saturday while La Rochelle reached the semi-finals for the first time.
Exeter, who narrowly beat Racing 92 in a gripping final last October as they achieved an English/European double, scored three tries but could not withstand the Leinster pressure as Jordan Larmour scored twice for the Irish province at Sandy Park.
La Rochelle, meanwhile, became the first of three French sides who will play in the semi-finals with a 45-21 demolition of English side Sale at the Stade Marcel Deflandre.
Centres Raymond Rhule and Geoffrey Doumayrou both scored twice and there were tries also for Gregory Alldritt and Dillyn Leyds as La Rochelle reached the last four for the first time.
"It's a reward for the players... to create a little bit of history for themselves and write a new chapter in this proud club's history," said La Rochelle coach Jonno Gibbes.
"Going into the semi-final for the first time will be a massive challenge."
La Rochelle are guaranteed to be joined by two other French teams as Sunday's ties see Bordeaux-Begles host last year's beaten finalists Racing 92 while four-time champions Toulouse travel to Clermont.
- 'Valiant effort' -
Exeter made the perfect start on home turf as wing Tom O'Flaherty touched down twice in the first eight minutes to open up a 14-0 lead.
Leinster hit back swiftly with one wing James Lowe reducing the deficit and the other wing Larmour levelling on the half hour.
Ross Byrne, who came on as a replacement for a groggy-looking Johnny Sexton, converted the latter and added two penalties to give Leinster a 20-14 lead at the break.
Within two minutes of the restart, Exeter were back within a point after Dave Ewers crashed over but three penalties from Byrne, who finished with 17 points, and Larmour's second try saw Leinster take control.
Exeter threw themselves at the Leinster defence but the blue line held firm and with the clock in the red Rory O'Loughlin thought he had crossed for the Irish side's fourth try.
The video ref ruled it out for an illegal tackle but Leinster had done enough to book their place in the final four.
"Exeter showed their class in the first 10 minutes so we knew it was going to take a valiant effort," Leinster centre Robbie Henshaw told BT Sport.
"It was up there with the toughest games we have played all season. It was up there with international standard."
- French Rhule -
La Rochelle were made to wait until the 30th minute for their first try against Sale.
After France flanker Alldritt's opener, winger Leyds capitalised on a mistake by fellow South African Faf de Klerk to race through for the second.
Sale's Irish-American fly-half AJ MacGinty, who scored 32 points in their last 16 win over Scarlets, kept the English Premiership side in touch and a try from centre Sam James right before half-time meant they only trailed 18-16 at the break.
The second half, however, belonged almost exclusively to La Rochelle as Sale struggled to play the 'heavy metal rugby' that coach Alex Sanderson had promised.
"It's a learning curve and you've got to lose them to win them," said Sanderson.
Two minutes after the restart another South African made an impact, with Rhule touching down under the posts, West converting.
With the French pack becoming increasingly dominant, it was only a matter of time before La Rochelle added to the score.
It came after 52 minutes when Sale full-back Simon Hammersley was unable to deal with Brice Dulin's long kick allowing Rhule to snap up his double.
Ten minutes later the tie was effectively over as Rhule fed fellow centre Geoffrey Doumayrou for the fifth try who added a sixth swiftly after.
Byron McGuigan gave Sale a crumb of compensation just before the end but it is the French side who progress to the semi-finals.