Chelsea rocked, Manchester United's Anthony Martial makes instant impact

Jose Mourinho refused to condemn his Chelsea flops after their Premier League title defence was plunged into turmoil as Steven Naismith`s hat-trick gave Everton a 3-1 win on Saturday.

London: Jose Mourinho refused to condemn his Chelsea flops after their title defence was plunged into turmoil by a 3-1 defeat at Everton, while Manchester United's Anthony Martial exploded onto the Old Trafford stage with a superb strike in his new club's 3-1 victory over Liverpool on Saturday.

Mourinho's side made a miserable start at Goodison Park as Scotland forward Steven Naismith came off the bench to score twice in the space of five minutes mid-way through the first half.

Nemanja Matic pulled one back for Chelsea before the interval, but Naismith completed his treble in the closing stages to condemn the Blues -- with three defeats and only four points from their five matches -- to their worst start to a season since 1988.

It left Chelsea 11 points below leaders Manchester City, who snatched a late 1-0 win at Crystal Palace, but Mourinho claimed he had no complaints about his team's performance and blamed bad luck for their recent woes.

"I am a champion, the players are the champions, the way they are playing is not as bad as the results, but in every single game things are going against us," Mourinho told BT Sport.

"We have to cope with it. Football is about results. It's easy to say and I agree completely, but results are too bad.

"I don't blame my players and I don't blame myself. I don't accept the results."

At Old Trafford, Martial made one of the more memorable United debuts in recent memory as the teenage French striker came off the bench to mark his debut with the clinching goal against Liverpool.

Signed from Monaco on transfer deadline day for a reported initial fee of £36 million ($55 million) that even United manager Louis van Gaal admitted was "ridiculous", Martial had been dismissed in some quarters as a panic buy.

But the hefty price tag, that made the 19-year-old the world's most expensive teenage player, didn't seem to bother Martial, who came on as a 65th minute substitute and settled one of English football's heavyweight clashes with a devastating knockout blow.

United had taken a two-goal lead thanks to Daley Blind's sumptuous long-range finish in the 49th minute and an Ander Herrera penalty in the 70th minute following Joe Gomez's foul on the Spanish midfielder

But the hosts were clinging to a 2-1 lead after Christian Benteke's brilliant bicycle kick in the 84th minute had given Liverpool hope of snatching a draw.

That was the cue for Martial to steal the spotlight two minutes later as he took possession on the left, surged past Martin Skrtel and cut inside before calmly steering his shot into the far corner.

"Anthony Martial scored a marvellous goal and physically he can play in the Premier League," van Gaal said.

"He's been with us for three days, that is too short to judge his personality but he made a very good impression."

Early pace-setters City sit five points off second placed United after they won 1-0 at Palace courtesy of a last-minute goal by substitute Kelechi Iheanacho.

City had earlier lost Sergio Aguero through injury, but prevailed when 18-year-old Nigerian striker Iheanacho poked in the rebound from a Samir Nasri shot to preserve the visitors' 100 percent record.

Aguero was forced off in the 24th minute after a heavy challenge by Scott Dann, which saw Kevin De Bruyne come on for his City debut following his £54 million ($83.3 million, 73.5 million euros) switch from Wolfsburg.

"I think the team is demonstrating why we have won five games," said City manager Manuel Pellegrini, who hopes Aguero will be fit to face Juventus in the Champions League on Tuesday.

"Last season is in the past and now we are thinking about the future. It's important to have a gap between champions, but three or four teams can be very strong and can win the title."

The result left Alan Pardew's Palace fourth, six points below City and a point behind United and Arsenal, who won 2-0 at home to Stoke City.

After Alexis Sanchez had twice hit the post, Theo Walcott put Arsenal ahead from Mesut Ozil's pass in the 31st minute and Olivier Giroud sealed victory with a header five minutes from time.

Elsewhere, Swansea City saw their unbeaten start to the season ended in a 1-0 defeat at promoted Watford.

Norwich City beat fellow promoted side Bournemouth 3-1 to claim their first home win of the campaign.

The day's other game saw Southampton draw 0-0 at West Bromwich Albion.