Arsene Wenger has warned Arsenal`s Premier League rivals that the Gunners are back in the title race with Alexis Sanchez ready to lead their charge.
Gunners forward Sanchez inspired a 5-2 win at Leicester on Saturday that, combined with Manchester City`s defeat at Tottenham, left Wenger`s men just three points behind new leaders Manchester United.
Sanchez bagged a hat-trick to open his account for the season and signal the end of a below-par start to the campaign from the Chile international.
And Wenger believes Sanchez is back up to speed following his close-season efforts at the Copa America, while his team are ready to challenge City, United and champions Chelsea for the title.
"Sanchez is back to his level. He won a big competition with Chile -- the Copa America -- and to adjust again to a competitive level when you come back takes some time," said Wenger.
"We could see in training already a different player in the last week or two.
"He showed that in this game and overall I thought we always looked dangerous going forwards.
"I think I have plenty of players who are world class but you always have to understand what the definition of that is.
"Overall he is a striker who is mobile and works hard for the team and when the team plays well he can score goals."Sanchez`s treble, plus goals from Theo Walcott and substitute Olivier Giroud, gave Arsenal the perfect response to last weekend`s ill-tempered 2-0 defeat at Chelsea.
Now Wenger`s men, who also won at local rivals Tottenham in the League Cup in midweek, are targeting a similar reaction in the Champions League, where they host Greek side Olympiakos on Tuesday looking for an improvement on their 2-1 defeat at Dinamo Zagreb in their first European outing of the season.
They could welcome back Francis Coquelin from a knee injury but they will be without Mathieu Flamini, who limped off in the first half at the King Power Stadium.
Jamie Vardy gave Leicester a 13th-minute lead but Walcott levelled for the Gunners five minutes later before Sanchez struck three times to make it 4-1.
Vardy`s second goal of the game a minute from full-time made it 4-2 and put him at the top of the Premier League goalscoring charts with six for the season.
But Giroud scored for the Gunners in stoppage-time to cap a win that ended Leicester`s unbeaten start to the season.
"We are sad because we wanted to continue to be unbeaten but I think when you play against Arsenal, United, Chelsea, City, that`s bonus points for us if we get anything," Leicester manager Claudio Ranieri said.
"It`s important to learn something but now the reaction is important in the next match. The players showed the maximum character.
"The quality of the Arsenal players is a very high level. We tried to do our best and created good chances and some were unlucky.
"It`s important how we react in the next match now.
"Sanchez is fantastic. I`ve known him since when he played in Italy and when he plays at this level he is an amazing player and can do everything. The ball and him are both together."