inadvertently played a part in his new club's downfall, having previously mentored the Saints boss.
Adam Lallana's second-half strike proved the difference in what was for the most part a dull and frustrating encounter at St Mary's.
The 1-0 victory was only Saints' second in 10 league attempts as they collected a first home clean sheet since October, having conceded 11 goals in those five previous matches.
That represented quite a drop off by what had been the sternest backline in the Barclays Premier League and former Argentina defender Pochettino was pleased to see them looking strong again.
"I think the evolution as of late has been good," he said. "I think the team has progressed a lot.
"I think the team as of late has been playing better, but it has been lacking defensive solidity.
"I think today we recovered that, we recovered that winning spirit, we recovered that solidity at the back.
"The most important thing about this team is that regardless of that fact it has been facing some struggles, it has kept on believing in the work that we do and how we play.
"That winning mentality has kept throughout the tough period."
The return of goalkeeper Artur Boruc after six weeks out with a fractured hand played a major part in the clean sheet, with his fine save preventing Shane Long grabbing a late equaliser.