England international Sterling made it six goals in five games, moving on to 27 strikes in all competitions, his best scoring tally in a single season.

His opener and a goal from Gabriel Jesus, who ended Sunday's (AEST) match with two assists, ensured City was in complete control by half-time after making six changes to its starting XI.

Sterling netted again and Bernardo Silva scored before the hour mark as Brighton, which remains eight points clear of the bottom three, had no answer.

Nine minutes before the end, a determined Sterling grabbed his third.

Jesus and Eric Garcia had already missed early chances by the time Sterling put the visitors in front after 21 minutes.

He cut inside from the left and impressively found the far corner from 20 yards after collecting Jesus's headed lay-off.

Jesus had a shot deflected onto the crossbar by Brighton defender Lewis Dunk and also showed some great footwork to create a chance which Riyad Mahrez narrowly fired wide.

But City was not to be denied, Jesus tapping in from under the crossbar after Rodri had helped on a Kevin De Bruyne corner a minute before the break.

De Bruyne cannoned a free-kick off the post shortly after the restart and City soon got their third after 53 minutes when Sterling headed in Mahrez’s in-swinging free-kick from inside the six-yard box.

It was four in the visitors' next attack when Socceroos No.1 Ryan could not hold Bernardo Silva's deflected effort and Jesus kept the ball alive to allow the Portugal international to convert a simple follow-up.

Sterling’s hat-trick goal came in unusual fashion, as he forced his way past Dunk and Adam Webster before somehow creeping a header between Ryan's legs while he fell to the ground, with a scrambling Dan Burn then helping it over the line.

City had lost its past three Premier League away games, while it had scored just three times in its past six top-flight matches on its travels, despite an expected goals figure of 13.

It had no issues bringing those poor runs to a welcome end with a victory that all but secures second place in the Premier League after Chelsea's defeat against Sheffield United.

Convincing home defeats against Manchester United, Liverpool and now City mean Brighton is not yet mathematically safe. Facing Pep Guardiola's side is a formidable task at the best of times, but its defending did the club no favours here, with City players constantly finding themselves unmarked close to goal.

Brighton can seal safety when it plays away to Southampton in its next fixture.