(Reuters) - - Chelsea demolished the team that succeeded them as Premier League winners when champions Leicester City succumbed tamely 3-0 at Stamford Bridge on Saturday.

Goals from the Premier League's leading marksman Diego Costa, Eden Hazard and Victor Moses ensured Leicester boss Claudio Ranieri's visit to his old club was a far cry from five months ago when the Foxes received a guard of honor for their title triumph.

The unmarked Costa's seventh-minute strike was his seventh goal of the season, before Chelsea's dominance was further rewarded, following more comedy defending, by Hazard's expertly-taken second.

Moses finished a brilliant one-two 10 minutes from time to leave Leicester as the first English top-flight champions since Blackburn Rovers 21 years ago to lose their opening four away games of the season.

Leicester's 2015-16 fairytale always looked an impossible act to follow but the tame nature of their fourth defeat in eight games was alarming for their fans who witnessed just three league losses over the whole of last season.

The visitors, who seemed to have half an eye on Tuesday's Champions League clash with FC Copenhagen as Riyad Mahrez was rested, were largely outclassed, leaving Ranieri perturbed.

"Yes, I didn't recognize them (his players) and I must speak to them about why (this happened)," the Italian said.

"Copenhagen is a well-organized team and if we do not react, it will be a very bad match on Tuesday."

Leicester faltered quickly. A low corner from Hazard was flicked on by Nemanja Matic through to Costa, who had all the time and room in the world to hammer home with his left foot.

After David Luiz had hit the post with one of his searing free kick specials, Chelsea's supremacy was further aided by Robert Huth and Luis Hernandez getting in each other's way when trying to cut out a Matic pass.

The ball bobbled off Hazard's head and into his predatory path with the Belgian nipping around the onrushing Kasper Schmeichel before slotting home.

Leicester, now possessing the worst defensive record away from home in the league, showed more resolve after the break and came close to narrowing the gap when Luiz deflected a Marc Albrighton cross against his own post.

Chelsea's mastery was almost underlined with a goal for former Leicester hero, man of the match N'Golo Kante, but his goalbound strike was kept out by Wes Morgan. "We miss him," Ranieri said of his French international midfielder.

For under-pressure Chelsea manager Antonio Conte - several British bookmakers had in the week suspended betting on him being the next Premier League manager to lose his job - there was welcome relief with the Italian hailing the performance as his side's best of the season.

(Reporting by Ian Chadband, editing by Ed Osmond)