Malky Mackay had a stay of execution last weekend but he was a condemned man on Thursday night after his Cardiff team were outclassed at home by Southampton, who arrived with no wins and four defeats from their previous six games.

The Welsh club had identified it as a must-win fixture in their battle to stay clear of the relegation zone but they leaked three goals in the first 27 minutes to leave their controversial owner, Vincent Tan, determined to terminate Mackay's two-and-a-half-year reign as manager.

Informed sources indicated that the two men, who did not speak on Thursday, will meet on Saturday, when Cardiff are at home again, in a relegation scrap with Sunderland. Asked whether he would still be in charge come Saturday, Mackay said: "It's something you will have to ask someone else. I've not heard any more. I've got belief in my ability to be the manager here. I'm standing strong. Overall this football club are competing well in the Premier League. We are not in the bottom three at the half-way stage.

"This was always going to be a tough season for us, but I firmly believe we can stay in this league and build on that as Southampton have done. It's about making sure that we stay focused on that task. It's very important that we stop washing our dirty linen in public. Where we are at the moment is where I thought we were going to be. Fighting hard in a tough battle to stay up. The three clubs who were promoted are all playing catch up."

There were protests against Tan and in support of Mackay before and during the game, the fans giving voice to their new anthem, Don't sack Mackay. Tan, who has rebranded the club in red, was also reminded that Cardiff would "always be blue" but it is all destined to count for nothing. After this shocking defeat the Malaysian tycoon will be even more inclined to dismiss the supporters' complaints. Whether it would have been different had Cardiff taken the lead, as they should have done after 11 minutes, will never be known. Craig Noone's cross picked out Peter Whittingham who, five yards out, made a ghastly hash of a sidefoot volley. His profligacy was punished five minutes later when Jay Rodriguez demonstrated how the sidefoot finish ought to be executed, tucking away Adam Lallana's squared pass from the right at the far post.

In the 20th minute Rodriguez struck again, catching Kevin Théophile-Catherine somnolent as he stole in to dispatch Ricky Lambert's cross from deep on the right and within another seven minutes Mackay was doomed. Another lofted ball into the penalty area found the Cardiff defence wanting as a header from Rodriguez set up Lambert for a routine finish from six yards.

By this stage the noise was all coming from the Saints' fans, cheering their team's superior passing game. For all Mackay's professed confidence Cardiff resembled a Championship team playing above their station, their attempts to reduce what was always a decisive deficit undermined by the failure to retain possession for any length of time. For the second half they sent on Andreas Cornelius, their £8m Danish striker, in place of Peter Odemwingie and within five minutes the substitute threatened with a glancing header from Whittingham's corner. It was a case of flattering to deceive. Cardiff huffed and puffed to no avail and were left with easily their worst result in the Premier League. If they were playing for their manager's future, you would hardly have guessed it. They have now won one and lost five of their last eight, scoring just four goals in the process.

In contrast, Southampton were excellent, with the much-coveted Lallana an outstanding man of the match. Deservedly, the Saints are marching in the right direction again. Their manager, Mauricio Pochettino, described it as "amazing performance and an amazing result", adding: "We were superior and deserved to win. We attacked and defended very well."