It is hard just now to know whether it is the performances of Chelsea or Manchester United which provide the more damning illustration for how Jose Mourinho’s once stunning coaching career is suffering an equally spectacular plunge. Mourinho’s current problems at United are well documented but perhaps even more revealing is how, with largely the same group of players as last season, Antonio Conte continues to inspire Chelsea’s revival.

From being only a point off the relegation zone and fully 20 adrift of then leaders Leicester City when Mourinho left shortly before Christmas last year, Chelsea are back as legitimate title contenders again themselves.

A run of four straight Premier League wins – including that 4-0 victory against Mourinho’s United – has put them back into a top four with Manchester City, Arsenal and Liverpool that is separated by just a single goal. Such form has been underpinned by not conceding a single Premier League goal since Gary Cahill, David Luiz and Cesar Azplicueta came together in a back three but, while the formation is new, the attacking inspiration is again coming from a familiar source.

In beating Southampton here 2-0, Eden Hazard was excellent in scoring Chelsea’s first and then creating their second to take his own personal league goal tally for the season to five. He managed only four during the whole of last season.

Similarly, Diego Costa is now on a run of eight goals in 10 Premier League games after contributing only 12 through the whole of last season. It was ultimately a comfortable for Chelsea, even if Southampton were actually first onto the front-foot. Manager Claude Puel would have identified those areas behind Chelsea’s wing-backs as a potential area of vulnerability and Dusan Tadic did quickly drift into space. He cut inside and then back outside the Chelsea defence before flashing a dangerous cross along the six-yard line. It seemed like the pattern for the match had been established but a combination of some slick Chelsea passing and slack Southampton defending soon completely changed the match.  

Hazard had driven forward into space down Southampton’s left that had been vacated by Ryan Bertrand and darted into the penalty area following an exchange of passes with Victor Moses. Steven Davis attempted to track Hazard’s run but was then much too hesitant with his attempted tackle as Hazard dragged the ball back inside and smashed a low angled shot between the legs of Forster.

Only six minutes had elapsed but Chelsea already had Southampton exactly where they wanted. They simply sat deep, with wing-backs Moses and Marcos Alonso as deep-lying as any full conventional full-back, either side of a three-man central defence. N’Golo Kante and Nemanja Matic were also content to defend deeply and break-up Southampton’s attacks before launching rapid counters for Pedro, Hazard and Costa. It could barely have worked better and so, even with possession statistics that were heavily weighted in Southampton’s favour, the best chances were all falling to Chelsea.

Hazard again burst forward and had a curling shot saved by Forster before Matic dispossessed Jordy Clasie and then put Costa clear on goal. His finish just lacked precision and was blocked by Forster’s leg but he more than made amends from an even more difficult position.

Hazard provided the assist this time and, from 25 yards, Costa cut inside and took advantage of a defensive lapse in concentration by Cuco Martinez to shuffle inside and curl a wonderful finish past Forster.

He then had several chances for a second but was just unable to meet Hazard’s cross before failing to finish when Hazard had squared after Forster had only parried Moses’s powerful drive. Puel responded by bringing on Sofiane Boufal – the scorer of a wonder-goal in the League Cup on Wednesday – but the closest they came to troubling Chelsea was when Sam McQueen crossed for Austin, who had just drifted offside before finishing past Thibaut Courtois.