Vale, who finished as runners-up to Neath last season, were hoping to move into the second half of the season with their noses in front of the Welsh All Blacks, but Johnstone’s 70th minute try put paid to those plans.
John Williams and Aaron Bramwell put the visitors ahead at the break with tries that made it 10-3. But a second penalty from James Leadbetter in the 65th minute gave Keys the boost they needed and Johntone put his side ahead for the first time with 10 minutes to play.
Vale piled on the pressure in the closing stages and Wales U21 international fullback Bramwell had two penalty attempts to rescue the result. Both drifted wide, and with back row man Steve Tandy grabbing a bonus point try for Neath at Swansea in the dying seconds of his side’s 27-14 win at St Helen’s, it was all change at the top.
Gareth King, Kevin James and James Merriman put Neath in control of the big Ospreys’ regional derby clash and former Wales outside half Arwel Thomas added two conversions and a penalty.
Nicky Thomas landed three penalties for the All Whites in the first half to keep his side in contention at 15-9 and a try by skipper and prop Andrew Clatworthy on his 100th appearance for the home side kept them in touch. But Neath were too strong in the end and that Tandy try means Neath will take a two point lead over Vale at the top of the table into the New Year.
Bridgend fullback Gareth David maintained his magical touch over the festive season as he kicked two penalties in each half to break through the 100 points mark for the season and steer the Ravens to a 12-7 home win over fourth placed Glamorgan Wanderers.
On Boxing Day, David sped away for the match-winning try against local rivals Maesteg and this time his boot was too good for a lacklustre Wanderers side who bagged a try by fullback Gareth Knight and a conversion from Aled James.
Aberavon outside half Jamie Davies won the battle of the boot against rising Ospreys star Gareth Owen as the Wizards hit back in the second half to beat Maesteg 25-21. Davies ended with 17 points with five penalties and a conversion, while Wales U19 cap Owen hit the mark with three penalties and a conversion.
The home side didn’t take the lead until the 64th minute and then had to come from behind a second time when Owen landed his third penalty. Each side scored two tries: Paul Bamsey and Simon Peters crossing for Aberavon and Grant Epton and Phil Wheeler scoring for Maesteg.
Bedwas fullback Jason Tovey scored all the second half points as the home side comfortably beat Newport 21-8. A try by Matthew Pizey helped Bedwas into an 11-3 interval lead before Tovey crossed in the second half as he claimed 13 points.
Outside half Dan Evans helped himself to 18 points as Llanelli beat Llandovery 28-3. Evans scored one of the visitors’ three tries and also kicked two conversions and three penalties.
In the 5.30pm kick-off, Cardiff moved to within two points of the leaders with a 23-10 win at Pontypridd. The Blue and Blacks had to play for the majority of the second half without back row man Damian Welch, who was sent off in the 43rd minute by referee Hugh Watkins for punching.
Despite that disadvantage, the visitors were too strong for the indisciplined home outfit and six penalties from former Wales U19 star Leigh Halfpenny were crucial. Ryan Howells got the Cardiff try and Ponty had a try from Trystan Lazarus and a penalty and conversion from Neil Burnett.
