Leinster's defence of their Celtic League title is in tatters after they lost their fourth match on end - 18-23 to Scottish new boys Borders.
Leinster now have to win their final two matches, secure two bonus points and hope other results go their way if they are to make the quarter-finals.
Edinburgh thumped a poor Llanelli outfit 38-14, while Ulster ended Munster's unbeaten run with a 26-17 victory at Ravenhill.
Scrum-half Neil Doak, an Ireland cricket international, scored all of Ulster's points to add some spice to the Pool A table.
Neath all but confirmed a quarter-final berth with a comfortable 34-7 win over Ebbw Vale, thanks to a hat-trick of tries to fullback Gareth Morris.
Vale flanker Tyrone Morris must have broken a record when he was sin-binned 30 seconds after coming on as a replacement, in his first appearance since being red-carded against Caerphilly a fortnight ago.
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.