Claude Puel admitted Chelsea’s early goal made it too much of an uphill battle for Southampton in the clash between the in-form sides at St Mary’s.
Eden Hazard’s sixth-minute strike set the Blues on course for a 2-0 win, as Saints lost at home for the first time since they were beaten by the same opposition eight months ago.
Puel said: “It's a disappointment. We played a great team, of course, but it's hard to take a goal so quickly, in their first action of the game.
“This changed the profile of the game, because after that it was easier for them to play their game, to stay strong behind, with good blocks, and after that to take spaces and make counter-attacks.
“We tried to play a good game, but this team was very clinical today and scored two goals with few chances. We tried to get back, but we left spaces.”
Reflecting further on the early goal, which was later followed by a superb Diego Costa strike, Puel added: “It was very hard. They defended very well every time.
“It's difficult to play against this team, because they have a good counter-attack and they are good defensively. We tried, but it was difficult to find a solution. Against great players it's difficult.”