Teimana Harrison was sent-off on his 100th appearance for the club as Saints suffered Anglo-Welsh Cup semi-final heartbreak at Bath on Friday night, going down 13-12
With time running out and Saints leading a tight encounter at a rain-soaked Recreation Ground 12-10, Harrison was sent off just 13 minutes from the end for a headbutt on Bath's Nathan Catt.
Josh Lewis kicked the resultant penalty to edge the home side in front, and Bath held on to book their place in the final at Kingsholm next Sunday.
Saints for their part will look back on a spirited performance in terrible conditions in the west country, but they came away empty handed, with Harrison's rush of blood a key reason for that.
The contact on Catt was minimal, and the Bath man certainly made the most of the situation, but Harrison will be ruing his indiscipline, which left referee Adam Jones with little choice once he had consulted the TMO.
The result means the Saints' season is effectively over, with Alan Gaffney's men not going to get relegated and not going to make the top six in the Aviva Premiership.
In terrible conditions at the Recreation Ground, with the rain pouring down as it had done for much of the day, the home side started strongly and took a very early lead when Lewis landed a penalty after just three minutes.
The home side were having the better of things in the early exchanges, and on 19 minutes their superiority told.
Saints scrum-half Cobus Reinach delayed a clearance and was caught in possession following a Saints lineout in their own 22, and after intense Bath pressure, Levi Douglas pounced on the loose ball to score a try and put Bath 8-0 ahead.
Lewis landed the conversion to see Saints fall 10-0 behind, and things were looking bleak for the visitors.
But a handling error from the restart immediately gave Saints a lifeline, with Myler landing a penalty to reduce the arrears to 10-3.
Bath were continuing to apply most of the pressure, but Saints were defending superbly, and when they ventured into the home side's half they were making it count.
A deliberate knock-on from Lewis handed Myler another penalty chance on 28 minutes and he made no mistake to make the score 10-6.
Just three minutes later it was 10-9, Myler landing a penalty after a blatant kick forward from a clearly offside Lewis, who was yellow carded for his efforts.
It meant Saints had a man advantage for the rest of the half, but they failed to make it count, and indeed it was Bath who had the chance to extend the home side's lead with the last kick of the half, but former Saints man James Wilson sent the ball wide.
The rain kept on pouring in the second half, with both sides resorting to a kicking game in the hope of handling errors.
Lewis missed an early penalty chance to extend Bath's lead, and there was little between the sides in the west country mud, but Saints gradually began to get a stranglehold on proceedings for the first time in the game.
On 55 minutes a mistake from Bath handed Saints a penalty chance, and Myler made no mistake from just outside the 22 to put the visitors into the lead for the first time.
Bath responded strongly as the weather deteriorated, with puddles of water appearing all over the sodden pitch.
But Saints held firm in the face of pressure from the home side, until the rush of blood from Harrison, on his 100th appearance for Saints, saw him red carded with 67 minutes played.
Harrison was unhappy with a challenge from Bath's Catt, and as the two squared up he moved his forehead towards the Bath man, who immediately appealed to the referee that he had been butted.
There was minimal contact, but there was intent, and after consulting the TMO, referee Jones red-carded the Saints man to leave them with 14 men for the remainder of the game.
To rub salt in the wounds, Lewis popped over the penalty for Harrison's indiscretion, and Bath were back in front at 13-12.
The visitors were now right up against it, and although Saints plugged away to try and respond, they never looked like creating any sort of scoring opportunity.
In the end, a knock-on from Saints as they battled to run the ball out from their own 22 saw the end of proceedings, and it is Bath who go on to the final.