James Bree smashed home a 30-yard volley in the first minute of injury time.
Russell Martin was delighted to see his Southampton side win for the first time this season with two late goals and believes the 5-3 Carabao Cup success at Cardiff City Stadium will have been good for his younger players.
Martin gave five players their first starts and was very happy to see his new £15m striker Mateus Fernandes hit the target. Another recent recruit, Cameron Archer, also scored twice.
“I’m really happy with the win and I’m pleased for my young players. But there is also a lot to be annoyed about,” said Martin.
“We conceded three goals and the game descended into chaos in the second half. It was a moment of brilliance for their first goal from a player I have admired for a long time (Rubin Colwill), but we took our foot of the gas and dropped their intensity.
“That was a big learning curve for the younger players. They took some liberties in the first half and they will be better for the experience and they showed real grit.
“I thought James Bree was outstanding and we wanted the team to put pressure on the players who are playing in the Premier League. They did that and it will have be a great night of learning for them.”
Bree smashed home a 30-yard volley in the first minute of injury time to give the Saints the lead for the fourth time in the match and break the hearts of the home players and fans. Then Archer added a final flourish with a fifth goal.
Cardiff has hit back three times to level and could have snatched a winner from Cian Ashford before Southampton’s late charge.
“We can take a lot of positives from the game when we see the youngsters playing against a Premier League club,” said Cardiff City boss Erol Bulut.
“We had it in our hands at one stage and had Cian Ashford hit the target with his big chance it might have been different.
“But they showed their quality and experience in the end. It was disappointing to concede just a few minutes into added time. It would have been nice and exciting to have taken it to penalties.”
“In the first half we showed them too much respect and I told them that at half-time. In the second half we used a high press and it was good.”
Bulut was also full of praise for his first goalscorer Colwill, who smashed a 30-yard effort into the top left corner. He also had a hand in the third goal from Alex Robertson.
“We expect things like that from Rubin because we see it from him in training. But we need him to play like that for 90 minutes and not just 30,” added Bulut.
“We need that level from him consistently in every game he plays.”