Key takeaways: 

• Marcos Alonso's goal secured Chelsea became the third Premier League team to net 100 goals in all contests this season, after Liverpool (119) and Man City (114).
• Chelsea set a horrible week behind them to return to winning ways in devastating style with the six-goal destruction of Southampton.

Having been defeated 4-1 at home to Brentford in the Premier League and then suffering a 3-1 loss to Real 

Madrid, Chelsea jumped back in a way that will give Thomas Tuchel motivation his team can recover their Champions League tie in Spain next week.

Tuchel stated that "things are upside down" after two bad results, but his players reacted by striking the woodwork three times and netting four in an excellent first half at St Mary's Stadium.

Timo Werner struck the post and headed against the bar inside the opening seven minutes before Marcos Alonso shot the visitors ahead after Mason Mount's assist.

England midfielder Mount's neat finish from outside the box doubled the lead, and then Werner was blocked by Fraser Forster's fine save as Southampton cracked in front of their fans.

Werner was shortly celebrating his first Premier League goal for six months after blasting through, and finishing before Kai Havertz made it 4-0 with a tap-in after Germany team-mate Werner struck the woodwork for the third time.

Southampton was blown away, and it needed a tremendous one-handed block by Forster to stop an own goal by Mohammed Salisu before half-time.

However, the Saints did concede a fifth in the 49th minute, Werner tapping home his second after N'Golo Kante had been thwarted.

Mount earned it six from close range on an embarrassing afternoon for Ralph Hasenhuttl and his Southampton team.