Narberth's 22-15 win over UWIC saw the Otters edge towards the Swalec Division One West title but they may be left to rue the failure to secure a bonus-point.
But their failure to do so leaves an opportunity for TATA Steel to snatch the league lead when they take on the same opponents on Wednesday.
Narberth recorded three tries in their win, through winger Matthew Davies, prop Tom Slater and replacement winger Nick Jones. Jon Campbell and Andy Berry crossed for the Students, who remain mired in mid table.
If TATA secure a try-scoring bonus point and win by six points in midweek they will overtake Narberth by virtue of points scored, and they warmed up in style with a 45-11 over Llanharan.
Centre Gbemi Fisher, full back Cameron Clement and outside half Simon Evans all crossed for braces, with number eight Cameron Davies also scoring.
Clement added five conversions to finish with a final tally of 20 points.
Meanwhile Tondu secured a priceless win in the battle to avoid the drop as they earned a 27-20 over visiting Waunarlwydd at Pandy Park.
Tries from Dan Thomas, Matthew Davies and Steve Brown gave the Waterwheelers a 27-6 halftime lead, and, despite a fightback from the visitors, it was enough to climb up two places to tenth.
Ammanford take their place at the foot of the table after succumbing 44-7 to a rampant Bridgend Athletic side at Newbridge Fields.
James Olds, Lyndsey McCausland and Jonathan Phillips crossed for first-half tries, and Phillips converted all three and added three penalties to give the hosts a 30-0 interval lead.
Rhys Ward Jones and Michael Hathaway touched down after the break as Athletic condemned the Recreation Ground outfit to a 10th straight loss.
Bonymaen's situation also looks perilous, but they did at least pick up what could be a crucial bonus point in a 31-28 loss at Llangennech.
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.