A fourth straight home win in the Premier League in what was the toughest game of the run, but it came at a cost.
A win is a win and every Saints fan would have taken a 1-0 win at the start of the game, however they didn't know just how difficult it would be as they were forced to dig in and play most of the game with ten men.
It all started so well though, Saints were on top and lead through Yoshida's goa in the 9th minute, it could well have been a two goal cushion with Cedric Soares ghosting in from a pin point Shane Long cross which needed a smart save from Adrian to keep out the header.
But the Hammers started to get on top of the game and after the half hour mark had taken control and Forster had to make a top knotch stop to make sure Saints went in at the break with the lead intact.
West Ham started the second half as they ended the first, they had a bounce about them that was missing from the Saints side, the team was flat and lacking a little something and the same could be said for the crowd who seemed to have little enthusiasm.
Then came the moment that changed the game with barely 10 minutes gone after the break, Wanyama had only to control a slow moving ball under no pressure, he completely failed to do so and when he turned to retrieve it he didn't have things all his own way, perhaps he was feeling agrieved because he then through himself into a tackle which was badly mistimed rather than malicious, perhaps another ref would have taken that view but Mark Clattenberg seems to relish controversy and he was soon reaching for a red card.
Was it merited ? possibly ! but this was the third such red card for Wanyama this season, he s getting a reputation as a player who is big and strong, but always walking a tightrope.
This looked a game changing moment and West Ham fans might have thought that it was about to change in their favour, certainly many Saints fans did, however it was Saints who actually benefited from the dismissal, it roused the crowd and it raised the team and although West ham would have a lot of the ball from now on they did little with it.
Ronald Koeman made a switch straight away after the red card, he took of Mane and brought on Oriol Romeu and this was a key switch Romeu had a control and mobility that Wanyama was lacking, yes it was backs to the wall stuff, but the fact was that the Hammers for all their huffing and puffing could not muster a decent attempt that threatened Forster's goal.
Their tactics were clear, they passed the ball well, but Saints kept them doing it far from goal, the arrival of Andy Carroll meant that the Hammers passed it around a lot near the centre circle, got it out wide and crossed for their big man, trouble was Jose Fonte and Virgil Van Dijk were perhaps not bigger but they were stronger and they lead by example.
Indeed it was Saints who had the only two real clear cut chances of the second period, Shane Long harassing a mistake from the visitors back four and firing just over, Charlie Austin nearly gave Saints a cushion late on after great work from Romeu opened up the Hammers defence but the latest Saints signing fired just wide.
You knew that there would be a lot of injury time and in fairness to Clattenberg who tried to make himself the centre of attention by holding up his arm and waving it dramatically at the crowd and TV cameras every time Saints went to take a free kick or throw in, the five minutes he added on was probably about right, the extra minute or so he put on after that seemed more for his benefit than West Ham's who by now had shot their bolt.
So a victory that asked questions about Saints, from a negative side the story was all about how Wanyama again got an unnecessary red card, a pat of his game that will surely be putting off potential suitors and also the fact that like the game at Upton Park, Saints after a positive start let the game slip from their control, long before Wanyama's exit.
From a plus point, the team spirit was once again there and players who some fans were questioning their ability a few weeks ago are truly showing their quality, the likes of Soares, Clasie, Romeu & Long have all had their detractors this season, but once again they proved those doubters wrong.
Soares especially is looking the real deal both defensively and in attacking play, he is putting the ghost of Nathanial Clyne to rest.
Likewise Jordy Clasie, another great display from him and he like Soares is now showing just why Saints bought them.
But at the end of the day it was all about three points and they were gained and the Hammers were roped in and are now within two points, a top six finish is a real possibility now and we have a run of games that if we come through unscathed will truly cement that from being a pipedream to reality.