Chelsea roared back to form as two goals each by Timo Werner and Mason Mount and first half strikes by Marcos Alonso and Kai Havertz sealed a 6-0 Premier League win over Southampton at St. Mary's Stadium on Saturday.

Chelsea went up 1-0 in the eighth minute as Alonso ran on to a deft flick by Mount and blasted in his first league goal since the opening day of the campaign.

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Mount, Chelsea's leading scorer in the league this season, equalled his tally of nine goals from the previous campaign with a superb shot from outside the box after Southampton's shaky defence failed to deal with Ruben Loftus-Cheek's cross.

Southampton's implosion continued as Werner made up for his earlier misses by beating Jan Bednarek for pace before rounding Fraser Forster and finishing into an empty net. Havertz then swept in Chelsea's fourth after Werner hit the post again.

It was the seventh time Southampton conceded four or more in the first half of a league game under Ralph Hasenhuttl, raising fears among home fans of another humiliation along the lines of 9-0 defeats by Leicester City and Manchester United they suffered in previous seasons.

A relentless Chelsea were rewarded again after the break as Werner tapped in a rebound from N'Golo Kante's effort which was saved by Forster. Mount completed the rout with another simple finish in the 54th minute.

"It gives us confidence to get back winning and have that feeling. I said before every game is a final and that started today. We need to carry this on," Mount said.

It was the perfect tonic for the European champions, who were beaten 3-1 by Real Madrid in the opening leg of their Champions League quarter-final on Wednesday after being thrashed 4-1 by Brentford last weekend.

Victory also helped Chelsea maintain their push for a top-four finish, with Thomas Tuchel's side third in the table with 62 points from 30 matches. They visit Madrid on Tuesday before next weekend's FA Cup semi-final against Crystal Palace.

"It was a good performance and a well deserved win. It's a tough stadium to come to but we made it look easy. In possession we were focused so it's a good performance and an excellent result," Tuchel said.

"We wanted to play with the same attitude but we have a lot of matches in the legs so we managed the game after that. It's easier when you lead than when you are down but it was a good mentality."

A deflated Southampton, who are 13th with 36 points, welcome Arsenal next Saturday.