Plymouth mifielder Lilian Nalis hit his first goal for the club to cast further doubt over Brighton's future in the Coca-Cola Championship.

This was a sixth straight defeat for Mark McGhee's side, who have scored just twice in their last seven matches, and the most worrying aspect of this loss was the lack of response from the visitors after the break.

In the second period they failed to test the Plymouth defence and never looked like levelling Nalis' opening goal, which came nine minutes before half-time.

McGhee could only look on enviously as veteran Frenchman Nalis, who arrived on a free transfer from Sheffield United in January, showed bags of composure to loft the ball past goalkeeper Wayne Henderson following a goalmouth scramble.

It proved enough to earn three points for a Plymouth side who have moved into a comfortable mid-table spot with a run of just two defeats in 10 matches - in total contrast to the fortunes of the visitors.

The Seagulls' struggle against relegation is looking increasingly desperate and they were keen to force the issue from the very start at Home Park.

With his side struggling for goals, youngster Joe Gatting had a couple of decent early efforts, with one strike being saved by goalkeeper Romain Larrieu and another flying wide.

On-loan Portsmouth man Vincent Pericard has had a decent start to his Argyle career and was Plymouth's main early threat, although his header from a Lee Hodges cross was straight at Henderson.

As Tony Pulis' men gradually got themselves into the game, it was David Norris' turn to head straight at Henderson but there were still too few chances.

But that all changed in the 37th minute when a poor Henderson punch led to a goalmouth scramble.

The ball eventually fell to 34-year-old Nalis, who made Henderson pay for his error, steering the ball home with a cool finish.

The visitors were clearly rattled and Nalis and Nicky Chadwick both went close as Plymouth searched for a second before Sebastien Carole drove over just before the break.

Argyle were clearly not going to rest on their advantage and Hodges and Nalis had further efforts, which failed to trouble Henderson, with Anthony Barness having a drilled effort blocked by Guy Butters at the beginning of the second period.

It seemed McGhee's half-time team-talk was having little effect as his side struggled to make an impression on the game and the home team continued to pour forward.

Restored to the midfield, inspirational Plymouth skipper Paul Wotton was next to threaten, driving over the bar from 30 yards before substitute Micky Evans had a close-range strike stopped by a desperate block from Adam Hinshelwood.

Adam El-Abd and Hinshelwood, who blocked a late Evans strike, then went into the book as an indication of the visitors' anger - and the Seagulls will need to improve greatly to avoid League One football next term.

Teams:

Plymouth Larrieu, Barness, Doumbe, Aljofree, Capaldi, Norris,Wotton, Nalis, Hodges, Chadwick (Evans 66), Pericard.

Subs Not Used: Buzsaky, McCormick, Zebroski, Djordjic.

Goals: Nalis 37.

Brighton Henderson, El-Abd, Hinshelwood, Butters, Lynch,Carole, Hammond, Carpenter, Frutos (Mayo 63), Kazim-Richards,Gatting (McPhee 80).

Subs Not Used: Reid, Nicolas, Martin.

Booked: Hammond, El-Abd, Hinshelwood, Butters.

Att: 13,650

Ref: P Joslin (Nottinghamshire).