Josh O'Neil put the visitors on course for back-to-back wins on the hour, and although Southport equalised Sam Haines won it with 10 minutes left to keep Poulton out of the premier division's bottom two.
There was a surprise home defeat for Thornton Cleveleys against Slyne-with-Hest.
Having fallen behind on the stroke of half-time, Thornton levelled through Richard Wright four minutes after the restart only for the visitors to net twice more for a 3-1 victory.
TC are still 10 points clear at the top but second-placed Euxton Villa have two games in hand.
Two late goals sealed a 4-2 home victory for mid-table Blackpool Wren Rovers after Tempest United had twice pulled level.
Jack Arrowsmith scored the only goal of the first half and doubled his tally two minutes from time to seal the points. In between, Kian Makepeace and Dejay Delacruz had both restored Wrens' lead after the visitors hit back.
Liam Gledhill gave Lytham Town a dream start at home to Vickerstown with a second-minute goal. But the visitors were level by half-time and it remained 1-1.
Third-placed Wyre Villa lost ground on the top two in division one wit a 3-0 defeat at Hesketh Bank. The home side scored all their goals in the first half.
The home side scored all their goals in the first half to move six points clear of Wyre, with leaders Milnthorpe a further eight ahead.
Only one game was played in the top flight of the Blackpool and Fylde Sunday Alliance but it was one to savour between the top two, writes MARK CAMPBELL.
Highfield Social were sitting pretty at the top of the premier division when they welcomed Fleetwood FC but it was the visitors who emerged 6-3 winners.
That saw Fleetwood replace Highfield in pole position on goal difference, both teams nine points clear of JD Blackpool South in third.
Movement at the top of division one as well as West Coast Sports pulled level with leaders Armfield FC courtesy of their 4-2 win over A&P Autos.
But West Coast have played four more games and so need Armfield to slip up.
Third-placed Re Italiani closed the gap on the leaders to three points thanks to a 9-1 victory over Blackpool Town.
Division 2A has new leaders in Spen Dyke after they toppled former top dogs AFC Broadwater 5-2.
Clifton Rangers are two points off the pace in third after a 5-2 home win over Belle Vue.
This division’s other game saw Highfield climb off the bottom after beating Marton Athletic by the only goal of the match.
Thornton Wanderers strengthened their grip on second spot in 2B with a 3-0 victory over Freckleton, while Fylde Coast Football beat Cleveleys 2-1.
And finally, Sencat and Albion played out a thrilling all-division one tie in the Sunday Trophy. This highly entertaining contest ended 5-5 and it was Sencat who won through 4-2 on penalties.