Will Buckley scored for the second successive Championship game as Brighton won at Peterborough to remain in touch of the play-off places.
Buckley netted both his team's goals at London Road, grabbing his first after a mistake by goalkeeper Joe Lewis.
Peterborough substitute David Ball equalised from close-range, giving the hosts hope of a draw.
But Buckley bagged the winner with a clinical finish from the edge of the penalty area.
Changes were inevitable for Brighton after they were taken to extra-time and penalties by Wrexham in the FA Cup in midweek , and boss Gus Poyet made four.
But Brighton looked fresh and created chances from the start, with Matt Sparrow and Craig Mackail-Smith each coming close.
The visitors eventually went ahead after Sinclair fouled Adam El-Abd wide on the left, and Buckley floated the resulting free-kick over Lewis's head into the net.
Peterborough responded well and Peter Brezovan had to get down to deny Sinclair before Ryan Tunnicliffe sent a shot over the crossbar.
Sparrow threatened again early in the second half but Posh were soon on the offensive again and Taylor tested Brezovan with a 20-yard drive.
Ball levelled after 72 minutes, scoring from close range after being teed up by Tunnicliffe.
It looked like that would be enough to earn a point but, with two minutes remaining, Buckley beat Lewis with a drive from the edge of the box that flew into the roof of the net.
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