After a thrilling Round 5 in the Champions Cup, only one club has definitely sealed a quarter-final place so far. With all to play for in this weekend's finale, we look at the possible twists and turns ahead.

Pool 1
Ulster Rugby hold a one-point advantage over La Rochelle heading into the final weekend as they bid to reach the knockout stages for the first time since 2014. A win at Wasps on Sunday afternoon will guarantee Les Kiss’ side a quarter-final berth. La Rochelle know they must win, while Wasps can yet sneak into the equation by beating Ulster. With this being the last pool to finish, all protagonists will know what's necessary to grab a best runners-up spot, if there is one still available. The twists and turns will be fascinating to follow on Sunday afternoon.

.@TommyBowe14 ???

Full video ?? https://t.co/hmGPlXM6NJ pic.twitter.com/BqJOiuIry7
— Ulster Rugby (@UlsterRugby) January 16, 2018

Pool 2
Saracens are facing a very unfamiliar situation, knowing that a home win may not be enough to avoid early elimination from the competition they have won for the past two years. Even a bonus-point win over Northampton Saints will see them waiting nervously for results elsewhere to see if they can finish as one of the three best runners-up. ASM Clermont Auvergne v Ospreys on Saturday afternoon is a straight shootout for automatic qualification. A draw would see Clermont go through.

Pool 3
Leinster’s 55-19 win over Glasgow Warriors on Sunday confirmed them as Pool 3 winners and guaranteed a home quarter-final. Exeter are currently in second, a point ahead of Montpellier. Rob Baxter’s side will remain as runners-up if they get a bonus-point win at bottom side Glasgow Warriors. Montpellier, who host Leinster, will have to better Exeter’s result. Whoever does finish second will then await scores elsewhere.

"We want to put in a massive performance against Montpellier."

Watch to hear more from @LukeMcGrath93... #MONvLEI pic.twitter.com/7sKvBmV0x1
— Leinster Rugby (@leinsterrugby) January 15, 2018

Pool 4
Leaders Munster know a bonus-point win at home to Castres Olympique next Sunday afternoon will guarantee top spot. Racing 92 travel to Leicester Tigers and must better Munster's result or face the perils of the best runners-up calculator. Castres and Leicester will be looking to finish their disappointing campaigns with a flourish.

Pool 5
There will be a packed house at Parc y Scarlets on Saturday for the winner-takes-all clash between Scarlets and RC Toulon. If Toulon lose that game they could feasibly finish level with Bath on 17 or 18 points (depending on bonus points), presuming the West Country side win at Benetton Rugby. In that scenario, Bath will finish second as they have the better head-to-head record on points difference. With a points tally currently better than any other second-placed side, the runner-up here is likely to go through.

??| We're pleased to announce the signing of @CVUNA, who has joined @bathrugby until the end of the season ?? https://t.co/Q8BiCZ7XK4 pic.twitter.com/F3MUBNX9lr
— Bath Rugby (@bathrugby) January 17, 2018