The Saints trailed by two goals at half-time after Demba Ba and Eden Hazard volleyed the Blues into the lead at Stamford Bridge but managed to rally in the second half thanks to a header from Rickie Lambert and brilliant volley from Jason Puncheon which delighted the boss.
"We came here with a gameplan," he told Sky Sports. "Obviously Chelsea are a good side and if you give them space they're going to hurt you.
"So we came here to put a block in and to try to intercept and then go on and counter-attack.
"The two goals we conceded - we could have cleared them a little bit better in the penalty area and the one just before half time could have been a big sucker punch.
"But it was great character from the players - to come out in the second half and stick to that gameplan - and great impact (from the substitutes) coming off the bench and to go and claw two goals back."