Timo Werner scored a first-half brace to give the hosts some breathing space before Danny Ings brought the Saints back into it after rounding Kepa Arrizabalaga just before half-time. Che Adams made it 2-2 but Chelsea hit straight back through Kai Havertz to restore their advantage. Alas, they couldn't see it out until the full-time whistle as Jannik Vestergaard salvaged a point for Southampton in injury time with a well-placed header.
From an attacking standpoint there are very few teams in English football who can compete with Chelsea. They move the ball around quickly, build out from the back well and exploit open spaces with absolute ease whenever they move into the final third. They are relentless in their pursuit of goals and there's a lot to be said for their cardio as a result of that.
After gifting Southampton possession on several occasions you'd think Chelsea would begin to learn their lesson, but that never really seemed to be the case. The Blues' off-the-ball positioning is really lacking across the pitch and with that, it's easy to determine that they just don't have great chemistry as a team yet. It should come in time but right now it's really costing them at the back.
Manager rating out of 10
5 -- There's a constant negative energy that stems from Frank Lampard on the touchline and that translates into what happens on the pitch, mainly due to his stubbornness. He so often decides to stick with the status quo by leaving the starting XI to it and hoping for the best, and whenever they do concede, there never appears to be anything resembling a Plan B. There's always an element of second-guessing in his management and that just doesn't work at this level.
Player ratings (1-10; 10 = best, players introduced after 70 minutes get no rating)
GK Kepa Arrizabalaga, 4 -- The second-string keeper showed poor timing and decisiveness for Southampton's first two goals, highlighting his clear lack of confidence or authority between the posts.
DF Cesar Azpilicueta, 5 -- Always exhibits leadership and strength both on and off the ball but as the game drew on his decision-making did seem to suffer.
DF Andreas Christensen, 5 -- The Dane fares better with last-ditch defending as opposed to anything technical or tactical and the proof was in the pudding during the build-up to Ings' goal.
DF Kurt Zouma, 3 -- It was an uncharacteristically bad day at the office for Zouma and after a slow reaction for Ings' strike he really messed up with a diabolical back-pass for the Saints' second.
DF Ben Chilwell, 6 -- Very few full-backs possess the quality of delivery that the Englishman has but defensively speaking there are still many questions that need answering.
MF N'Golo Kante, 5 -- While he'll always be something of a general in the middle of the park, his distribution is starting to become more erratic.
MF Jorginho, 6 -- Needs to communicate more with Kante when they both push up the pitch but his distribution was fantastic, culminating in a lovely assist for Werner's second goal.
MF Christian Pulisic, 6 -- He was isolated for large spells of the game but the American showed real resilience on the ball and played a key role in Chelsea's third of the day.
MF Mason Mount, 5 -- Mount did little to impact the tempo and remained quiet going forward, overshadowing some nice defensive moments in the process.
MF Kai Havertz, 7 -- There's a real vision and poise to Havertz's style but he's still settling into life in the Premier League, combining a mistake for Southampton's first goal with a tap-in to make it 3-2.
FW Timo Werner, 9 -- Produced easily his best showing in a Chelsea shirt thanks to two brilliantly-taken goals and an assist to prove why he's so highly valued in world football.
DF Reece James, N/R -- Failed to provide extra protection for Azpilicueta as Chelsea let their lead slip late on.
MF Hakim Ziyech, N/R -- Got stuck in and showcased a real determination to make a difference for the Blues in his 20-minute cameo.
FW Tammy Abraham, N/R -- Tried to help kill the final few minutes of the game after being introduced late in the afternoon.