Holders Leinster comfortably assured themselves of a home tie in the European Cup quarter-finals with a 25-3 victory over French side Montpellier in Dublin on Saturday.
The Irish province, and fellow-two time winners Munster, who wrapped up their pool campaign with a sixth win in six games by seeing off Northampton 51-36, had already booked their place in the last eight last week.
Ulster had to make do with that as Clermont leapfrogged them in Pool Four, beating the 1999 European champions 19-15.
Ulster more than matched their hosts but fell just short of recording their first ever win on French soil with Clermont scoring the only try of the match in the second-half when Ti'i Paulo scrambled over the line.
Clermont join another French side, four-time champions Toulouse, in the last eight.
"Mission accomplished," said Clermont skipper Aurelien Rougerie. "We knew that this would be a very difficult match. The Irish are tough and a complete team."
Toulouse scraped through as winners of Pool Six despite being beaten by Gloucester on Friday thanks to Harlequins slip-up in Galway.
Leinster stormed into an early 17-0 lead over Montpellier with tries from Sean O'Brien and man of the match Rob Kearney - both converted by Fergus McFadden - looking like they were cruising to ensuring they earned a home tie in the last eight.
The full-back made no mistake as his momentum carried him over the line, despite being tackled, for his 13th try in 40 European Cup appearances.
Montpellier, who fielded a strong side as they prepare for a crucial Top 14 date with Stade Francais next Friday, did not crumble under that early assault and despite having the strong wind against them camped inside the hosts' 22 for the best part of a quarter of an hour.
However, they came away with nothing as the champions' defence held firm and McFadden, who had assumed the kicking duties after Jonathan Sexton was ruled out an hour before kick-off with an injury to his left ankle, extended the lead to 20-0 with a penalty shortly before the break.
Leinster wrapped the game up and achieved their objective of home advantage for the last eight when Cian Healy burrowed over in the 43rd minute for the hosts third try to make it 25-0.
Munster ran in four tries in a 51-36 victory over Northampton to maintain their perfect record in Pool One.
Scarlets defeated Castres in France 16-13 and qualified for the Challenge Cup quarter-finals.
Source: AFP Global Edition