Raheem Sterling's hat-trick inspired a 5-0 rout of West Ham as Manchester City commenced their quest for a third straight Premier League title in style in a contest where VAR played a prominent role.

The England star struck a sublime second-half treble after Gabriel Jesus prodded the champions ahead in the 25th minute of a one-sided affair at the London Stadium.

Sterling's well-worked first goal came six minutes after the interval and though a VAR review found he was offside before Jesus tapped in, he did find the net again 15 minutes from time to put City beyond the Hammers' reach.

He could have added the third from the spot after Issa Diop fouled Riyad Mahrez but gifted the spot-kick to Sergio Aguero, which the substitute converted on a re-take, awarded following another VAR intervention.

Sterling was not to be denied the match ball, though, as he raced clean through in added time to compound an embarrassing eighth straight defeat for West Ham in competitive meetings with Pep Guardiola's men.

The returning Mahrez - cleared to play by anti-doping officials having missed the Community Shield amid concerns over what he had taken for a procedure he had on international duty - went close with two attempts before instigating the opener.

The Algeria winger released Kyle Walker, whose deflected byline cut-back was neatly turned home by Jesus.

City moved up a gear after the interval and doubled their advantage when Kevin De Bruyne created space for Sterling to slide a finish under Lukasz Fabianski.

A VAR review denied Jesus a brace after Sterling was shown to have strayed marginally offside but the latter eventually made amends, timing his run to perfection as he cushioned Mahrez's pass and lobbed Fabianski.

Aguero headed to the spot in the 86th minute and got on the scoresheet at the second attempt, awarded after another VAR review found West Ham midfielder Declan Rice had encroached before clearing the ball that came to him after Fabianski had saved the initial penalty.

Sterling, fittingly, had the final say in stoppage time, guiding home the fifth following Mahrez's measured throughball.

What does it mean? City lay down early marker

Community Shield winners against Liverpool, Guardiola's men are already setting the pace in the Premier League.

The Reds, runners-up last term, put four past Norwich City on Friday and City rose to the challenge, completely dismantling a West Ham team that have European ambitions. They will take some stopping.

Sterling top of the class in City's five-star showing

With the club's all-time top goalscorer Aguero held back until the 69th minute, Sterling took it upon himself to tear holes through the Hammers after half-time.

Even though he continues to start in wide areas, the lethal 24-year-old has to be considered a contender for the Golden Boot.

Diop must do better in defence

Spared from conceding an own goal thanks to Jesus' decisive touch for the opener, Diop almost gifted one to the Brazilian on the stroke of half-time through sheer indecision.

The Frenchman then went missing for City's second and conceded the penalty that enabled Aguero to make it four.

West Ham need significant improvement after failing to sign a senior centre-back during the close season.

What's next?

City will get a sterner test at home to Tottenham next Saturday, the same day as West Ham's trip to Brighton and Hove Albion.