Newport went to the Gnoll with an unbeaten record in the Welsh Premier League, but left it with their tails between their legs as Neath ran riot.
The second-placed All Blacks pasted the Black and Ambers 37-8 on the back of two tries to speedy winger Richard Johnston and 19 points from the boot of teenage fly-half Matthew Jones. Neath could even afford to have veteran forward Mark Jones sin-binned - scoring 10 points in the 10 minutes that Jones was a spectator.
With Neath stopping a rampant Newport in their tracks third-placed Aberavon are nipping at the All Blacks' heels after a 32-11 win over a disappointing Pontypridd.
Centre David Hawkins and winger Daran Griffiths scored good tries to give the Wizards a 17-6 lead at the break, and there was no way back for the cash-strapped Valley Commandoes side. The margin would have been a lot greater if the Wizards had converted more than one of their six tries.
Fourth-placed Carmarthen Quins stepped clear of the chasing pack with a solid 46-6 victory over Ebbw Vale, with flanker Andrew Thomas scoring twice.
Veteran lock Paul Jones returned from his second drugs-related ban to lead Caerphilly against Cardiff at the Arms Park, but the Cheesemen never got close in a 45-3 mauling, and Jones' yellow card wouldn't have helped his humour.
The home side called on Blues regional players James Malpas, James Goode and Robin Sowden-Taylor for the match and the young forwards ran riot in an impressive six-try effort. Another promising youngster, fly-half Gareth McCarthy, scored 20 points to nail down Caerphilly's coffin.
Pontypool's free-fall down the table continues at a great rate with a 3-50 hiding at Llandovery, who stunned Pooler with an seven-try performance that clawed them clear of the relegation zone. Speedy young winger Ifan Evans scored a hat-trick.
Newbridge couldn't find three fit frontrowers so had to call off their trip to Llanelli, meaning the Scarlets had no chance to get off the bottom of the table.
Results: Aberavon 32 Pontypridd 11, Bridgend 25 Bedwas 20, Cardiff 45 Caerphilly 3, Carmarthen Quins 46 Ebbw Vale 6, Llandovery 50 Pontypool 3, Llanelli v Newbridge (called off), Neath 37 Newport 8, Swansea 34 Cross Keys 18.