Ulster put their recent slump in form to bed on Saturday as they beat La Rochelle 20-13 at Kingspan Stadium to go top of their pool.
Crossings from Rory Best, Jacob Stockdale and Nick Timoney saw them get the better of the French side, who claimed a losing bonus-point.
Pool 1 is set to go down to the wire next week as Ulster head to Wasps while La Rochelle host Harlequins in a thrilling Sunday's action.
On form it seemed unlikely Ulster were going to come out on top against a La Rochelle outfit that has shone in all competitions this season. And with the hungry visitors starting much the brighter, it seemed like only a matter of time before the Ulster try-line would be breached.
Ulster though managed to keep them at bay and would have been content to see Alexi Bales settle for the three points on nine minutes. He made it 6-0 seven minutes later after a line-out offence, which put La Rochelle in a strong position, despite losing Gabriel Lacroix to injury.
Lacroix's replacement, Paul Jordaan, was issued a yellow card on 23 minutes for taking out Charles Piutau in the air and that appeared to flick a switch for Ulster as they finally enjoyed possession and territory. In the closing 12 minutes of the half, they certainly clicked into gear.
First a line-out drive led to Best crossing wide out for an unconverted try and then, with four minutes remaining, wing Stockdale shrugged off Vincent Rattez's weak attempt at a tackle to move Ulster 10-6 in front, which was how the half finished after John Cooney's missed extras.
The game turned two minutes into the second-half though when Bales crossed near to the posts after Victor Vito's break from halfway. Bales added the extras and suddenly Ulster were playing catch-up at 13-10 down. La Rochelle finally had something to show for their efforts.
But their lead was short-lived. La Rochelle forced a play on their own 22 and number eight Timoney punished them, crossing for a converted try for 17-13 before Cooney made it 20-13 with a penalty on 50 minutes. That crossing gave the Kingspan Stadium faithful added confidence.
The closing half-an-hour was nervy battle for territory and La Rochelle were repelled after a series of close-range scrums and line-outs. Ulster also had chances to extend their lead and deny the French a bonus-point and despite not doing so, they were thrilled with the win.
Tries: Best, Stockdale, Timoney
For La Rochelle:
Pens: Bales 2
Yellow Card: Jordaan
Ulster: 15 Charles Piutau, 14 Craig Gilroy, 13 Louis Ludik, 12 Stuart McCloskey, 11 Jacob Stockdale, 10 Christian Lealiifano, 9 John Cooney, 8 Nick Timoney, 7 Sean Reidy, 6 Matty Rea, 5 Iain Henderson, 4 Alan O'Connor, 3 Rodney Ah You, 2 Rory Best (c), 1 Callum Black
Replacements: 16 Rob Herring, 17 Kyle McCall, 18 Ross Kane, 19 Kieran Treadwell, 20 Chris Henry, 21 Dave Shanahan, 22 Johnny McPhillips, 23 Darren Cave
La Rochelle: 15 Kini Murimurivalu, 14 Gabriel Lacroix, 13 Geoffrey Doumayrou, 12 Pierre Aguillon, 11 Vincent Rattez, 10 Jérémy Sinzelle, 9 Alexi Bales, 8 Victor Vito, 7 Kevin Gourdon, 6 Levani Botia, 5 Mathieu Tanguy, 4 Jason Eaton, 3 Uini Atonio, 2 Pierre Bourgarit, 1 Dany Priso
Replacements: 16 Jean-Charles Orioli, 17 Vincent Pelo, 18 Mohamed Boughanmi, 19 Gregory Lamboley, 20 Afa Amosa, 21 Tawera Kerr-Barlow, 22 Benjamin Nobles, 23 Paul Jordaan
Referee: Wayne Barnes (England)
Assistant referees: JP Doyle (England), Matthew O'Grady (England)
Television match official: Geoff Warren (England)