The West Berkshire side went into the clash in good spirits following a return of six points from three successive away games in Southern Division One South & West.
But they were still underdogs against a promotion-chasing Swindon side who had won five of their last seven matches without conceding a goal.
In a largely uninspiring match, the Kingfishers managed to keep the visitors out until the 68th minute when Bradley Gray nodded in from Josh Morse’s cross.
It remained 1-0 until two minutes from the end when Joey Tustain sealed the win with Swindon’s second goal.
Up next for Thatcham is a trip to Wimborne Town on Saturday (3pm ko).
Newbury Town
NEWBURY Town suffered their heaviest defeat of the season on Saturday as they were thrashed 9-1 at Oxford City Nomads.
The loss is Town’s sixth in a row and leaves them second from bottom in the Hellenic Premier Division.
Little went their way at Oxford as they fell 2-0 behind early on and lost skipper Carl Jenner to injury.
Brad Shaw reduced the deficit when he scored direct from a corner but Michael Miller was then shown a straight red card for a last-man tackle.
Oxford made the most of their numerical advantage by scoring twice before half-time to lead 4-1.
And it didn’t get any better for Newbury in the second half as they conceded five goals to complete a miserable afternoon.
Newbury face a must-win home match with basement side Abingdon Town this Saturday (3pm ko).
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here