Badshot Lea fell to a 2-0 defeat at home to Isthmian League South Central Division play-off hopefuls Hayes & Yeading United.
First-half goals from Adrian Clifton and George Sippetts gave the visitors a crucial three points in their push for a top-five finish in front of a crowd of 194 at Westfield Lane.
The Baggies got off to the worst possible start and fell behind in the first minute when Noah Hay’s cross was turned home by Clifton.
The visitors then doubled their advantage on 21 minutes when Sippetts controlled the ball in the box before producing a clinical right-foot finish into the bottom left-hand corner past Baggies keeper Jake Simpson.
Hayes nearly scored their third of the afternoon on the half-hour mark when the hosts failed to clear a corner and Jude Mason’s acrobatic bicycle kick went over the bar.
The Baggies nearly pulled a goal back in first-half stoppage time when a nice move ended with Samuel Yabani firing his effort over the bar.
The hosts created the first chance of the second half on 47 minutes when Charlie George curled his effort over the bar.
The Baggies then won a free kick in a promising position just outside the box in the 56th minute, but Steven Sylla fired his attempt over the bar.
Hayes nearly went 3-0 up on the hour mark when Herson Alves’ free kick fell to James Richmond, whose low effort from close range was well held by Simpson.
The visitors went close again in the 65th minute when Alves’ free kick found Mason at the back post, who headed over the bar.
Next up for the Baggies is a trip to Ascot United in the Isthmian League South Central Division on Easter Monday (3pm kick-off).