Coventry moved off the bottom of the table after sealing victory with goals in each half from Gary McSheffrey and Lukas Jutkiewicz.
McSheffrey, lacking support around him, raced forward at pace and drilled a low shot from 20 yards to make it 1-0.
Jutkiewicz scored his ninth goal of the season, heading McSheffrey's teasing cross in from six yards.
Brighton's Craig Mackail-Smith almost replied late on but his header was kept out by goalkeeper Joe Murphy.
Andy Thorn's side move off the bottom of the table on goal difference at the expense of Doncaster. Brighton failed to assert themselves and, as a result, were condemned to their fourth successive defeat.
Gus Poyet's team have now failed to score in their last four outings. Brighton did, however, have the first opening of the match but Adam El-Abd failed to direct Ryan Harley's cross on target.
Gary Deegan went close for the Sky Blues, shooting just wide from 18 yards, before the hosts went ahead 11 minutes before the interval through McSheffrey's effort.
Brighton had an opportunity to reply immediately, but Murphy kept out Mackail-Smith's shot from 12 yards.
Coventry added their second through Jutkiewicz's header and, after that, Brighton struggled to create openings.