Manchester City's new signing Omar Marmoush bagged a hat trick in 13 first-half minutes in a 4-0 rout of Newcastle United in the Premier League on Saturday, making an emphatic statement after arriving at the club last month.

James McAtee added a late strike for Pep Guardiola's side who climbed to fourth place in the standings on 44 points with their biggest league victory at the Etihad Stadium this season, while Newcastle slipped to seventh on 41.

"The way we played, we remembered what we were and what we have not been this season," Guardiola said. "We always try, but sometimes we cannot do it. We need to win these games to qualify for the Champions League. We have to make this kind of performance to send our people home happy."

Marmoush gave the hosts the lead in the 19th minute when City goalkeeper Ederson launched a long pass that defender Kieran Trippier misjudged and the Egyptian lobbed the ball over the onrushing Martin Dúbravka.

The 26-year-old doubled his tally five minutes later when he latched onto a pass from Ilkay Gündogan before firing in a low shot that took a slight deflection off Trippier.

The striker completed his hat trick in the 33rd with a blistering shot from 12 yards out when Savinho found him in acres of space.

"Amazing day, the feeling is crazy," Marmoush said. "And the three points, we came in from the first minute and got the job done. It was all fast paced, I was really happy to help the team."

McAtee struck in the 84th, nine minutes after entering the game, volleying home from Erling Haaland's near-post flick from a corner.

There were some tense moments when City's goalscoring machine Haaland pulled up holding his knee, while a distraught looking Guardiola held his head in his hands, but after receiving medical treatment he was able to walk off the pitch.

Playing with more confidence than they have shown in weeks, City attacked in waves against a Newcastle side who looked nothing like a team who had won 12 of their previous 14 games across all competitions.

City had seven shots on target to Newcastle's one, including a shot from Savinho after a one-two with Phil Foden that Dubravka managed to save.

Marmoush's emergence as a genuine attacking threat, after City paid 59 million ($74.25 million) to sign the striker from the Eintracht Frankfurt, is a big boost for the injury-hit team, who lost defender Manuel Akanji on Wednesday for eight to 10 weeks to an adductor injury that required surgery.

Marmoush -- who had only made two previous league appearances for City -- has been a breakout star in Europe this season, scoring 15 goals in the Bundesliga to trail only England international and Bayern Munich forward Harry Kane in the top scorers' chart.

He received a standing ovation from the delighted Etihad Stadium crowd and high fives from teammates when subbed off in the second half, and then walked proudly into the tunnel with the match ball tucked under his arm after the final whistle.

Newcastle have not got the better of City in a league game since a 2-1 victory in January 2019, and have never won a league game at the Etihad.

"It was a tough game, they are still the toughest team to play against. We were not at our best today," Newcastle boss Eddie Howe said.

"They ask so many questions of you, put you under pressure. They did not have a bundle of chances but they did what they needed to do."