Cross Keys caused a major shock by securing an unlikely 25-20 triumph at Principality Premierhsip leaders Llanelli.
A penalty try for the visitors was sandwiched between strikes from Owen Jones and Will Johnstone's second-half winner to influct Llanelli's third league defeat of the season.
Llanelli rallied through scores from Mike Davies and number eight Dan Godfrey and the result leaves the hosts one point clear at the top of the Princiaplaity Premiership.
The hosts looked to be cruising with a 17-10 half-time lead at Parc y Scarlets with Dan Evans adding two conversions and a penalty. But Cross Keys went ahead through the penalty try and Johnstone's 52nd minute try.
Evans added a penalty to reduce the lead to 22-20 but opposite number Joe Deakin, who had already hammered home two conversions and a penalty, calmly slotted home a 58th penalty to ease the tension and seal an unexpected win.
Meanwhile. Aberavon cruised to a bonus-point win against Bedwas at the Talbot Athletic Ground.
The Wizards kept their winning run going, after a 74-0 hammering of Division Three club Llantwit Fardre 74-0 in the SWALEC Cup last weekend, and recorded the four tries early in the game.
But they trailed the Premiership strugglers just minutes into the game, but took control early in the second half, scoring tries through flanker Chris Davies and winger Richard Carter within the first ten minutes after the restart.
Bedwas had no response and the kicking of outside-half Jamie Davies saw the game end 38-10 in Aberavon's favour.
Cardiff came from behind to beat Ebbw Vale 15-13 thanks to the contribution of a pair of replacements.
The Blue-Blacks had made nine changes from the XV that lost at Llanelli last week yet it was prop Richard Cornock, who didn't figure at Parc y Scarlets, who came off the bench to help Cardiff secure a win, as late on he pushed over to level the scoreline.
Another replacement, outside-half Gareth Davies, slotted over the conversion to hand the Blue-Blacks four points.
Newport claimed a stunning 34-32 victory over defending champions Neath in a thriller at Rodney Parade.
Tom Riley scored in either half and was ably supported by strikes from Mike Poole and Andrew Coombs in a match which saw the lead change hands nine times.
Neath hit back through tries from Luke Ford and David Lockyer to ensure a losing bonus point for the Welsh All Blacks.
Wales full-back Kevin Morgan started for Newport as the 48-cap star continues his recovery from a serious Achilles tendon injury.
And his influence spread to his fellow backs as early as the second minute when Riley crossed for the opening try.
Newport held a slender 17-16 advantage at the break and were pinned back by the goalkicking of Arwel Thomas who claimed a 22-point tally including six penalties and two conversions.
But Newport replacement kicker Dan Griffiths booted four penalties to get the hosts over the finishing line.
Leigh Bevan was the hero for mid-table Swansea who recorded a comprehensive 39-3 bonus-point victory over struggling Bridgend.
Wing wizard Bevan opened and finished the scoring in a convincing five-try triumph at St Helens.
The hosts were able to include Ospreys' scrum-half Rhodri Wells and his quick distribution allowed his fellow backs to produce free flowing running rugby.
Full-back Nicky Thomas grabbed the second try before adding four conversions and two penalties in an impressive 19-point haul.
Bridgend finally got themselves on the scoreboard when fly-half Gareth David's penalty grabbed their only points on a disappointing afternoon for the visitors.
But Swansea back-rower Sam Kiley added a third for the Whites to put Richard Webster men's into a commanding 22-3 interval lead.
Centre David Watts grabbed the bonus-point for the home side early in the second period before Bevan sealed victory with his second score.
There was a tie on Saturday at Glamorgan Wanderers and Pontypridd both scored 13.
Scott Sneddon scored a penalty with the last kick of the game to seal a stunning second-half comeback from the Wanderers.
The result leaves both sides safe in mid-table with little prospect of any end-of-season nerves at either end of the table.
Pontypool emerged narrow 10-6 victors over Llandovery in the Welsh Premiership basement battle.
Tries in either half from Sam Mills and Gareth Williams handed the bottom side only their fourth win of the season at Church Bank and leave them five points adrift of their nearest rivals.
It was a double celebration for Wales and Ospreys scrum-half Rhys Webb when he called at the home of Welsh rugby to help commemorate the first anniversary of Principality Stadium and his return to fitness this weekend ahead of the RBS 6 Nations.
Prior to their departure to Wellington for the next leg of the World Series, Wales trained with England and Ireland. WRU TV caught up with Owen Jenkins who revealed the 'buzzword' which is driving the Wales squad on.
Wales head coach Rob Howley explains his decision to change the captaincy of the national side with Ospreys second row Alun Wyn Jones taking over from Sam Warburton for the forthcoming RBS 6 Nations. Howley is hoping his decision will allow Warburton to rediscover his 'mojo'.
How do you follow a dancing hippopotamus - the Ospreys wheelchair rugby team has just the 'oneness' to do it say the BBC! For a decade the sight of a herd of hippos synchronised swimming around their own private blue lagoon, has lit up our television screens at regular intervals between favourite BBC One shows. But now the nation's most watched channel has relinquished its famous amphibious mammals in favour of a new show-reel which includes the Ospreys wheelchair rugby team.
Head coach Rowland Phillips and key front rower Carys Phillips look ahead to games against Spain and Ireland as Wales Women ramp up their preparations for the forthcoming Six Nations. The two warm-up games are a 'massive opportunity to refine the squad' according to the Welsh camp.
Martyn Phillips has discussed details of the newly published 'Strategy for Welsh Rugby' which puts in black and white terms the plans and direction of the governing body of the national sport in Wales for the next decade.
WRU chief executive Martyn Phillips has urged Welsh rugby fans to follow in the footsteps of their soccer counterparts at last summer's Euro Championship by backing their team to the hilt in the upcoming RBS 6 Nations campaign.
Chief executive Martyn Phillips has highlighted the plans for Wales to become a breeding ground for national and elite club rugby coaches, which are contained in the WRU's 10-year 'Strategy for Welsh Rugby'.
Andrew Coombs is enjoying his new role as Nelson forwards coach. The former Dragons and Wales lock has big ambitions to become a professional coach but feels it's important to learn the ropes in grassroots rugby and where better than his home club Nelson, with friends and family close to hand.
Students at Brynllywarch Hall School, near Newtown, have transformed their own lives, and are now having a positive impact on others through rugby. The sport has had a life-changing effect on the well-being of the students who are now delivering rugby sessions to local primary schools and playing for a new mixed ability side
Wales reached their first semi-final since 2013 in the opening round of this season's HSBC World Rugby Sevens Series in Dubai. WRU TV's Graeme Gillespie recaps on what proved to be an eventful tournament
Wales and Ospreys back row James King, who came through the North Wales age grade system, nominated North Wales Regional Community Rugby Manager Marc Roberts, in the WRU's 'Diolch' initiative where squad players thanked those who played a part in their rise to the top.
Beating Merthyr has boosted Carmarthen Quins hopes of reaching a top eight spot in the Principality Premiership. Quins captain Haydn Pugh is delighted with his team's progress and is determined that everyone from the Under 6s through to the senior team, enjoys the ride.
When the Wales squad were asked to nominate individuals who played a big part in their early playing days, Wales and Dragons full back and wing Hallam Amos thought of his former Monmouth School rugby coach John Bevan.