Leadership of the Blue Square North changed hands on Bank Holiday Monday with Southport overtaking neighbours Fleetwood Town.
That was due to Fleetwood being beaten at Workington and Southport winning 2-1 at Haig Avenue against Northwich Victoria.
Phil McLuckie`s 14th minute effort for Workington at Borough Park in front of 731 not only knocked the visitors off top spot but it also boosted the Reds` own play-off chances.
Port fell behind to a 27th minute Mark Danks goal for Vics, but were back on level terms right on half time through Michael Powell.
The crowd of 1,107 had to wait until the very last minute of normal time when Matty McGinn popped up with the home side`s winner.
It was a good day all-round for the majority of the play-off contenders, with all-bar Stalybridge Celtic winning.
Third-placed Alfreton Town earned a useful 2-1 win at the Rockingham Triangle against Corby Town, earning a 10th minute lead through Paul Clayton.
Jack Moult then put the Reds 2-0 ahead 7 minutes after half time, with Steve Diggin pulling one back for the Steelmen on 69 minutes.
Droylsden and Hinckley United also won to keep Workington out of the top five.
The Bloods edged Blyth Spartans 2-1 at the Butcher`s Arms with goals from Andy Brown on 14 minutes and Tony Gray`s 72nd minute penalty after Ian Graham had equalised on 35 minutes.
The Knitters won 2-0 at Redditch United with goals from Andy Hall after 11 minutes and Adam Webster after 29.
Stalybridge, meanwhile, went down to a surprise 3-2 defeat at virtually-doomed Vauxhall Motors.
Jonathan Egerton put Motors in front after 29 minutes and Karl Noon doubled their lead 8 minutes later.
Keith Briggs reduced the arrears just past the hour-mark only for Noon to make it game over with his second 4 minutes from time, despite Warren Peyton`s last-minute spot-kick reply.
AFC Telford United`s second successive Easter defeat, this time 1-0 at home to lowly Gloucester City, virtually ends their hopes of a top five finish.
Jack Harris was the Tigers` match winner with the only goal of the game in the 12th minute.
Elsewhere on Monday, a stoppage time effort from David Brown earned Eastwood Town the spoils at Coronation Park against Gainsborough Trinity, while Solihull Moors and Stafford Rangers shared a 1-1 draw at Damson Park in which both goals came within a minute around the hour-mark – Dom Merella for Rangers and a Jake Edwards spot-kick reply for Moors.
