Munster and Ulster are in Heineken Champions Cup action, the former in must-win territory away to Racing 92, while the latter can seal a quarter-final spot with victory in Clermont.
And in the Challenge Cup, the Dragons can take a giant step towards the quarter-finals in Castres, with Edinburgh also hoping to overhaul French leaders Bordeaux-Bègles and Zebre away to Top 14 strugglers Stade Français.
With that in mind, we have picked out five notable victories for Guinness PRO14 teams in France over the past five seasons (well six so we could squeeze in one of the more remarkable ones).
2018/19 – Toulon 17-28 Edinburgh
Let’s start with the most recent edition of the competition and Edinburgh’s momentous success in Toulon last season. While it was largely a down year for the French giants, it is worth remembering that they had only previously lost one home game in Europe’s top competition.
In Round 5 Edinburgh travelled to the Stade Félix Mayol in control of their group, but knowing a win would be needed to keep themselves in the hunt for a home quarter-final.
Toulon enjoyed the better of the first half, leading 12-8 with tries from Guilhem Guirado and Facundo Isa.
Darcy Graham’s score kept Edinburgh in touch, and in the second half they cut loose with 20 unanswered points.
We still can’t quite believe this Viliame Mata offload…😲
— Heineken Champions Cup (@ChampionsCup) June 7, 2019
Blair Kinghorn put them in front with a second try before Bill Mata produced a stunning offload – even for him – to send James Johnstone over for try number three.
While Julian Savea struck late for the hosts, Edinburgh ran out 28-17 victors.
2017/18 – Montpellier 14-23 Leinster
At first glance this might not seem like the most impressive Leinster victory in France, there have been a fair few after all.
But in 2017/18 Montpellier were an exceptional team at home, going unbeaten there in the Top 14.
In Europe they were narrowly beaten by Exeter Chiefs, but still a tough nut to crack in Round 6 when Leinster travelled to the Altrad Stadium in search of a win that would seal the number one seed.
Montpellier still had an outside chance of a quarter-final spot and led 14-8 at the break thanks to tries from Bismarck du Plessis and Yacouba Camara, both from attacking lineouts.
Ross Byrne had crossed for a try in the first half, and in the second, Leinster flew out of the blocks with 15 unanswered points.
First Robbie Henshaw got over before a Byrne penalty put Leinster back in front. And just to show they could also score through their maul, Sean Cronin grabbed a third to seal the win.
That top seed proved invaluable as Leinster saw off Saracens and the Scarlets in the quarters and semis before edging out Racing 92 in the final in Bilbao.
2016/17 – Racing Métro 14-23 Glasgow Warriors
The same scoreline as the game above but a very different encounter as Glasgow Warriors turned over a star-studded Racing 92 team.
That side included Leone Nakarawa – now back at the Warriors, as well as Dan Carter, and was crucial in the Warriors reaching the quarter-finals for the first time.
Juan Imhoff had given Racing an early lead, converted by Dan Carter, before Finn Russell – who has since replaced Carter at the French side – hit back with a pair of penalties.
Russell then put Alex Dunbar over for the first Glasgow try, giving them a 13-7 half-time lead.
And he was crucial again in making the break that set up Ali Price for the next Glasgow score.
Another Russell penalty looked to have made the game safe before Carter sliced through and past Stuart Hogg to get Racing’s second.
Still, Glasgow had a nine-point lead with seven minutes to go and they were able to see it out. They went on to finish second in their pool before falling to eventual champions Saracens in the last eight.
2015/16 – Toulouse 23-25 Ulster
While it may eventually have proved in vein, Ulster will look back fondly on their trip to Toulouse in 2015 when they secured an historic win away to the four-time champions.
Having beaten the French giants 38-0 at home the previous week, Ulster knew that they needed to complete the double to stay in touch with Saracens in the pool.
It may not have been the Toulouse team that is currently unbeaten in Europe this season, but a side with the likes of Gaël Fickou, Louis Picamoles and Thierry Dusautoir will never go down easily on their own patch.
Ulster started strongly with a Ruan Pienaar try helping them lead 10-3 at the break, with Andrew Trimble adding another early in the second half.
But a Fickou score and a Sébastien Bézy penalty put the French side back in front, only for Paddy Jackson to reply with a penalty before Luke Marshall struck with six minutes remaining.
Even so, Toulouse had one final throw of the dice, Picamoles forcing his way over, but they had left themselves too much to do as Ulster held on.
It was not quite enough to get out of the pool as they lost away to Saracens in Round 5, but if Ulster are looking for inspiration this weekend, 2015 should provide it.
2013/14 – Toulouse 14-16 Connacht
Apologies to Leinster and Glasgow, both of whom won in France in 2014/15, but we’re going to go back a year earlier for our final success.
Connacht had scored a combined three points on their two previous trips to France in Europe’s top competition prior to the 2013/14 season when they were drawn in a pool with Toulouse and Saracens.
They travelled to Toulouse in Round 3, facing a team who were coming off an away win against Sarries, and in one of the biggest shocks in the competition’s history, Connacht stunned their hosts 16-14.
Jean-Pascal Barraque’s converted try had put the home side 7-6 to the good at half-time, but Dan Parks slotted a third penalty to give Connacht the lead.
Kieran Marmion then scored a brilliant try after breaks from Robbie Henshaw and Fionn Carr to make it 16-7.
Toulouse responded through Thierry Dusautoir to cut the deficit to two with ten to go, but Connacht held out for what to that point was the most famous win in their history.
A couple of years later they would top that with success over Leinster in the Guinness PRO12 Final at BT Murrayfield.