The Shrimpers have lost just once in their first eight League One games and will defend their unbeaten home record against Oldham on Saturday.
Tilson expects the Latics to provide a stern test but is confident his in-form side can secure their second home win of the campaign after drawing three of their first four games at Roots Hall.
He told the club's official website: "I keep saying there are probably seven or eight teams you can name who will be up there at end of season, after that the league is that tight that anyone can beat anyone.
"It will be another tough game for us (against Oldham). We're going well at the moment, yes we've had too many draws but we've only lost one of our first eight games so the lads have got to take a lot of credit for that.
"It's important to keep the run going and we'll try and keep that going on Saturday."