Last Sunday, a missed shot at Newcastle cost his side two points. Yesterday, a missed punch cost them all three, although Leeds rarely looked like earning any of them.
The computer that determines these things ranked the two goalkeepers on show here as the best in the Premiership before this game. Some rapid reprogramming now looks in order after Martyn's error - an ineffective flap at a Palmer header from John Beresford's free-kick which allowed Egil Ostenstad to set up David Hirst at the far post.
Paul Jones' No 1 ranking rarely looked under threat thanks to a shot- shy Leeds attack, although a brave block early on from Rod Wallace and a flying save from the Leeds captain, David Hopkin, near the end demonstrated his pedigree.
Palmer's dismissal for a second bookable offence united the managers in sympathy and set up a nail-biting finish when Southampton had threatened to walk away with the game.
There is no doubt that the former Leeds player's challenge on Ian Harte 15 minutes from the end deserved a yellow card, but both the Southampton manager, David Jones, and his opposite number George Graham felt his first, for a foul on Gunnar Halle was harsh.
"As so often happens when they were down to 10 men, they got everybody back behind the ball and made it difficult for us," Graham said.
Palmer had been Southampton's most effective player, his gangling runs helping to create the chances that should have made it safe for the Saints long before his dismissal.
Hirst slid a cross from his fellow striker Ostenstad narrowly wide and rattled the crossbar with a powerful header from Matt Le Tissier's corner. But the best chance fell to Ostenstad, who was put through by Matthew Oakley but pushed the ball too far in skipping past Martyn.
Premiership survival for Southampton after this latest impressive victory over their so-called betters looks like mission accomplished. As far as Leeds' European ambitions go - on this display that looks like mission impossible.Reuse content