Portsmouth endured a nervy finish before winning 24-20 at relegation-battling Weybridge Vandals in London two south west.
The Rugby Camp outfit led 24-8 but were guilty of easing off and two quick-fire tries left them on the ropes.
Coach Ben Dudley was relieved to hold on.
He said: ‘We took our foot off the pedal but I am led to believe this is a game we would have lost last season, so it is evidence of progress.’
Portsmouth led 17-8 at the break through a Curtis Barnes try and a penalty try awarded just before half-time for a collapsed maul.
Andy Barnes struck two conversions and a penalty.
Jackson Clark then added a try at the start of the second half before they relaxed.
United Services eventually coasted to a 47-12 win at struggling Purley John Fisher in London three south west.
After taking a 12-0 lead, Services were pegged back to 12-12 at half-time before taking command late on.
‘We allowed ourselves to get dragged into a real arm wrestle,’ said director of Rugby Matt Davis.
Liam Geghegan scored twice, while Luke Davey, Will Rolfe, Ollie Bowles, Tom Knight and Ben Smith grabbed the other tries.
Southsea Nomads beat Southampton 29-10 at Furze Lane to leave Aaron Beesley a proud stand-in skipper.
‘It was very pleasing for everyone involved,’ he said.
‘We’ve had an up and down season but the boys were fantastic to finish our home fixtures on a massive high.
‘They showed great fight and spirit to get the job done in a professional manner.’
Alex Kasote, Dan Griffin and George Joyce all played their last home fixture in a Nomads shirt.