Paris - Billy Burns upstaged older brother Freddie to lead Ulster to a gritty 22-15 victory over Bath on Saturday to secure a spot in the European Champions Cup quarter-finals.
Clermont ran out 26-19 winners over Harlequins to top Pool 3, on 24 points, with Ulster, on 21pts, qualifying as one of the three best second-placed teams.
Four-time champions Leinster will be top seeds in the quarters after making it six out of six for an unassailable 28 points to top Pool 1 with an 18-0 win over Treviso.
Exeter also booked a home tie in the last eight with a 33-14 win over French outfit La Rochelle while Glasgow kept their slender hopes alive with a crushing bonus-point win at Sale.
Leinster, Exeter, Clermont, Racing 92, Toulouse and Ulster have all qualified for the quarter-finals with Northampton, Glasgow, Saracens and Gloucester vying for the other two spots.
Battle of the Burns
In Belfast, the battle of the Burns brothers went the way of Billy, whose successful move to Ulster has seen him picked for Ireland's Six Nations squad.
"We've got to be a lot better if we want to go further," Burns said.
"That's as tough a game as we've played here, all credit to Bath."
Burns added: "This group is hungry to learn and get better. I don't know who we'll be playing in the quarter-finals, but we'll look forward to getting stuck into it."
Springbok No 8 Marcell Coetzee opened the scoring for the home side, powering over from close range following an attacking line-out maul. In-form scrum-half John Cooney booted the extras.
Bath drew level through Ruaridh McConnochie, the England winger pouncing on a Freddie Burns cross-kick that evaded Jacob Stockdale on the bounce.
England cap Burns nailed the conversion.
Ulster kicked off the second period in perfect fashion, full-back Will Addison's smart offload setting Robert Baloucoune haring down his right wing for a try Cooney converted.
Burns senior clawed back three points with a penalty for Bath before Addison raced away for Ulster's third try following some slick midfield handling.
A Ross Batty pushover try for Bath set up what should have been a nail-biting final 10 minutes, but that petered out after referee Ruiz showed the replacement hooker a red card for a reckless shoulder charge into the face of Cooney, Burns hitting the penalty for Ulster.
Exeter had already qualified but needed to beat La Rochelle to secure a home tie in the last eight and after an awkward first half, came through to win 33-14.
The first 40 minutes was a nail-biter for the home supporters who saw tries from Luke Cowan-Dickie and Dave Ewers cancelled out by scores from Kini Murimurivalu and a penalty try.
Turning round at 14-14, the Chiefs moved up a gear in the second half and a double from number eight Sam Simmonds and a late touchdown from Stu Townsend secured the bonus point and a home tie in the quarter-finals.
Coach Rob Baxter was taking nothing granted.
"Everyone you face from now on will be very good," he told BT Sport. "Whatever happens it's going to be tough."
Northampton and Glasgow both kept their hopes of reaching the knock-out phase alive although the Saints have a better chance than the Warriors.
Northampton's bonus-point 36-24 victory at Lyon in Pool 1 means they now have 19 points, two more than Glasgow who hammered Sale 45-7.
Both teams will have to wait until Sunday's matches, where defending champions Saracens and Gloucester, both on 14 points, need bonus-point wins to sneak in.
Neither side has an easy task. Gloucester will need to turn over Toulouse in France while Saracens, rocked by the news that they will be relegated from the Premiership at the end of the season for salary cap breaches, must beat Racing 92 at Allianz Park.
European Champions Cup results on Saturday, the sixth and final round of pool matches (SA times):
Treviso (ITA) 0 Leinster (IRL) 18
Lyon (FRA) 24 Northampton (ENG) 36
Exeter (ENG) 33 La Rochelle (FRA) 14
Sale (ENG) 7 Glasgow (SCO) 45
Harlequins (ENG) 19 Clermont (FRA) 26
Ulster (IRL) 22 Bath (ENG) 15
Playing on Sunday:
Munster (IRL) v Ospreys (WAL) (15:00)
Saracens (ENG) v Racing 92 (FRA) (15:00)
Montpellier (FRA) v Connacht (IRL) (17:15)
Toulouse (FRA) v Gloucester (ENG) (17:15)
Quarter-finals: April 3-5
Semi-finals: May 1-3
Final: May 23 at Marseille, France