Former Oldham striker Sam Parkin came back to haunt his old club as Swindon pulled off an excellent 1-0 win despite playing most of the game with 10 men.
Defender Matthew Heywood was sent off after just 12 minutes, but Oldham missed the resulting penalty and their visitors went on to claim the only goal of the match through centre forward Parkin.
The former Chelsea man had a long spell at Boundary Park in the 2000-2001 season and there were major moves to sign him permanently but he chose Northampton Town before finding his way to Swindon.
Robins manager Andy King has always been grateful and he said Parkin and strike partner Tommy Mooney could spearhead a challenge for promotion.
King said: "They are the best two strikers in the division and we have got a chance if they play most of the games together.
â€œThis is a very important win because it keeps us right up there which is needed in such a tight division.
â€œI'm delighted with the players because they had to work very hard after the sending off and they managed to keep Oldham to shots from long range.
â€œOur goal keeper Rhys Evans made a couple of excellent saves when he was needed and the boy has a big future in the game." Heyward walked following a push at the far post as he challenged for a deep cross with Oldham centre forward Calvin Zola.
The decision was contested, but referee Mark Cowburn waved away protests and also gave Oldham a penalty which Zola hammered against the right-hand post.
Oldham missed another good chance on 24 minutes when Danny Boshell allowed Evans to spread himself and make an excellent block. The keeper was again in action as he brilliantly tipped over Zola's powerful header moments later.
The winner arrived on 61 minutes as Junior Lewis shrugged off a challenge and crossed for Parkin to slide home from six yards.
Oldham created little threat afterwards and only went close through a volley two minutes from time by substitute Carlos Roca.