Sterner tests await, that is certain, but Chelsea made an emphatic return to the Champions League and may have discovered a new cult hero.Davide Zappacosta marked his home debut with an outrageous goal. In truth, it was a fluke and yet it lifted Stamford Bridge and stunned Qarabag, the minnows from Azerbaijan.Never mind Diego Costa, still AWOL amid reports he was in Madrid inching towards a move to Atletico, all hail Zappacosta with his striking surname and apparent mastery of the cleverly-disguised cross.His strike was the second of the night and he was still charging up the flank to create the sixth for Michy Batshuayi in the closing minutes.Pedro Rodriguez soothed Antonio Conte's nerves with a fifth-minute opener and Cesar Azpilicueta nodded in the third, soon after the interval.Tiemoue Bakayoko, on as a substitute, scored his first Chelsea goal with the help of a deflection and Batshuayi helped himself to a couple as the visitors from Azerbaijan wilted.More importantly for Conte, here was a fourth successive victory since the shock defeat against Burnley. The Premier League champions are gathering momentum, a commodity he values highly.Since transfer window closed, Chelsea are looking once again like the ruthless machine they were last year: intense and focused on whatever task is to hand, revved-up by a high-energy manager on the touchline.Conte claimed there were risks involved in resting five players against a team with nothing to lose on their Champions League debut.With Atletico Madrid and Roma to come, he was aware no cheap points could afford to be surrendered at this stage.Ahead of the game he explained about the energy-sapping sequence of seven games in 21 days which culminates against Manchester City.As it turned out, Qarabag made it easier for him. They made a bright enough start, twice getting in behind Marcos Alonso in the first two minutes before Chelsea took a grip and refused to let go.Ibrahim Sehic, in goal for the visitors, began what was to be a busy shift with saves from Alonso and Batshuayi.Then he was beaten for the first time by Pedro, who swept a first-time strike inside the post when Willian collected a short corner and found him on the fringes of the penalty area.Willian forced another save from Sehic and Batshuayi was unable to convert the rebound before Zappacosta introduced himself to his new public at Stamford Bridge.Half an hour had gone when the athletic wing-back, signed from Torino on deadline day, strode across the halfway line, shrugging off two challenges as he went.He glanced up to check his options – Batshauyi and Pedro were up in support - and then he bamboozled Sehic with a mishit cross which swerved over the head of the goalkeeper and into the net.The Italian admitted afterwards: 'I'm really happy. It was a dream debut, scoring at Stamford Bridge. I'm happy for myself, but mainly for the victory to get us going well in the Champions League. To be honest I wanted to cross it