There has been a Welsh side in the Cup quarter-finals every season since the inaugural tournament in 1995-96, but with one round to go in this year's Pool rounds, only two Welsh regions are left in contention and neither side has an easy task.
Llanelli Scarlets need to beat Northampton Saints at Franklin's Garden - never the easiest place to get a victory - while the Celtic Warriors' fate is in the hands of Pool rivals Perpigan and London Wasps.
The Warriors' brave 16-15 win over Perpignan - last year's Cup runners-up - at the Brewery Field on Friday has kept their playoff hopes alive, but a win in their final match at Calvisano may not be enough. Lynn Howells' men then need Perpignan to beat Wasps, with neither side getting a bonus point.
"There is still everything to play for in this pool," Howells said. "What we must ensure is that we get a result in Calvisano and do everything we can to earn a bonus point.
"Perpignan only just beat Calvisano in Italy and they managed to score four tries against Wasps."
The Scarlets' path through is much simpler - a win or a draw over the Saints means they're in the quarter-finals. A loss means they're not.
Gareth Jenkins' side mauled the hapless Borders 53-7 on Friday night after another colossus performance from No 8 Scott Quinnell, and they will need the big man to be at his very best when they travel to Northampton.
The Dragons' hopes were ended - along with their unbeaten home record this season - when Leicester grabbed a 26-20 victory at Rodney Parade on Saturday.
Dragons fans packed the ground to catch a glimpse of their Springbok star Percy Montgomery and new signing Bob Skinstad, but it was another South African - Tigers fly-half Jaco Van Der Westhuyzen - who stole the show with two tries.
At the other end of the scale, the Neath-Swansea Ospreys remain one of only two teams in the competition without a point after five rounds, and never looked liked improving that record in their 15-33 loss to unbeaten Edinburgh.
The Cardiff Blues' unlucky season continued in Dublin, with a 79th-minute Brian O'Meara penalty goal giving Leinster a 20-17 victory.
The Blues earned their third losing bonus point of the season - the only Cup team to have so many narrow losses - and have the chance to finish their season on a high when they invite Sale Sharks to the Arms Park this weekend.