SIR ISAAC Newton has a lot to answer for.

If it wasn't for that damn apple falling on his head things might keep on going up and up rather than keep crashing back down to earth.

Saints have been something of a perennial apple on Newton's head this year.

We've talked enough this season about false dawns, wins or encouraging performances being followed up by disappointment when hope beckoned.

Last time round it wasn't a false dawn.

Saints had seemed to escape their gravitational downward pull. A win against Liverpool followed by a win against Portsmouth, then a favourable draw for a match that could yield a place in the FA Cup quarter-finals.

Then came the deadline day signings of Olivier Bernard and Henri Camara.

It seemed that this time the apple may finally stay in the air - or even on the tree.

But in the first 45 minutes at Birmingham it wasn't just an apple that fell but a whole orchard.

Birmingham came out brimming with confidence, with pace, with running, with determination and steamrollered Saints.

Harry Redknapp's side went into the match with the 4-5-1 formation that had provided such cause for optimism in their last two games but on this occasion it didn't work.

The gamble of pairing Bernard on his debut with the returning Jelle van Damme didn't pay off and they were exploited by the rampant Jermaine Pennant, also making his debut.

On the right role, trying to get forward to support Peter Crouch, was Kenwyne Jones but the position didn't look comfortable for him or at least he didn't adapt.

In that first half Birmingham were superb and made Saints look Saints - but they didn't help themselves.

Thank goodness for Antti Niemi in goal whose superb saves - most notably from a shot from distance from Jamie Clapham - kept Saints afloat.

After an early warning with a near miss from new Blues striker Walter Pandiani the debutant did open his account on 12 minutes.

Pennant burst down Saints' new-look left and crossed into the centre where Pandiani found himself allowed more space than he would have expected and steered home his header.

Five minutes before half-time Birmingham doubled their lead.

Mario Melchiot burst to the bye-line and cut back. Jamie Redknapp was already committed to the tackle and, with the ball gone, chopped down Melchiot.

There was no arguments with the award of the penalty and Robbie Blake stepped up to emphatically blast home into the top corner.

Saints struggled into half-time looking battered and groggy.

But the introduction of Camara was like the smelling salts that brought them back to their senses.

Who was this new team that had took the field? There was pace, purpose and grit.

Camara made an instant an impact. Saints reverted to a 4-4-2 with Jones having gone off and the new signing's electric pace caused all sorts of problems.

Just seven minutes after coming on to the field Camara had bagged his first goal. His express train running pulled him clear of the tracking defenders and he slammed a half-volley of a ball into the top corner of Maik Taylor's net.

It was a stunning introduction.

From then on Birmingham were worried every time Camara got on the ball.

Saints tried to play the ball in behind for him to run on to or up to Crouch to try and flick-on and put him free.

Camara thought he had equalised with ten minutes left but the ref had already blown for an infringement by Rory Delap, who might have scored himself.

David Prutton also missed a great chance when he was alert enough to catch Clapham in possession but burst into the area and fired over the bar.

Birmingham had still threatened through Julian Gray, with Niemi having to make good stops from Stephen Clemence and from Clapham's deflected effort.

But it was the Blues who were left hanging on at the end.

However, unfortunately for Saints, hang on they did and another vital chance to make up some ground on the pack ahead passed by.

That apple dropped again. The problem now is that it's gone past being just annoying and it gets more and more painful every time it lands.

That poisoned apple named relegation is still in the tree. Saints need to defy gravity and make sure it stays up there.