Arsene Wenger believes next weekend\'s match against Manchester City will prove the strength of Arsenal\'s Premier League title credentials this season. The Gunners have mounted a challenge after going eight league matches unbeaten, the latest win coming when Robin van Persie scored in a 1-0 win over Everton at the Emirates Stadium on Saturday. Victory gave Wenger\'s team, on Arsenal\'s 125th birthday, the psychological lift of being in the top four for the first time this season, although Chelsea could overtake them by avoiding defeat against league leaders City on Monday. But Wenger is still impressed with the improvement at Arsenal following their poor start to the season, and feels they could challenge for the title. \"The spirit is there the focus is there,\" the Frenchman said. \"It was a historic day and it\'s not easy to keep the focus. We try very hard to put pressure on the other teams, next Sunday against Man City is a big test to see where we are. You could not predict where we are today from earlier in the season. We started from so deep (in trouble) that no-one could have predicted where we are in December but we have to keep going.\" Victory over Everton was settled 20 minutes from full-time when van Persie was on the end of a floated pass by Alex Song, and powered home his volley off the post. \"We were historical because we won 1-0,\" said Wenger in reference to a scoreline often associated with the Arsenal teams of George Graham. \"And George Graham was here too. You would say we are van Persie dependent, he got us a goal at a moment when we were struggling to create chances,\" added Wenger after the Dutch striker\'s 33rd league goal of the calendar year. He delivered something special and three important points. Goalscorers get all the plaudits. Robin deserves that because he has always been remarkably consistent.\" Arsenal great Thierry Henry, who addressed fans before the match, was pictured applauding van Persie\'s stunning goal. The Gunners have not won a trophy since 2005 and it is now nearly four years since former France striker Henry, currently with the New York Red Bulls, left for Barcelona. Henry, 34, has been training with Arsenal recently but Wenger said: \"At the moment Thierry Henry goes back on 15 January for a training camp. \"We lose Marouane Chamakh in January for the African Nations, we lose Gervinho and defensively we are short, but we have Andrey Arshavin and Alex Chamberlain who has made great progress. If there is an opportunity somewhere for them, then why not? Park Chu-Young as well.\" Everton lost Louis Saha to injury which harmed their chances of a shock win. They could have fallen behind in the first half but Gervinho had one effort saved by Tim Howard and another deflected over the crossbar with just full-back Tony Hibbert in front of him. Aaron Ramsey also went close, but van Persie eventually sealed the points with his goal. \"It was a terrific finish,\" said Everton manager David Moyes. \"You could question how he made the run, but the finish was terrific. It was a really good goal that beat us. We went for them and that left us open in the first half. We stuck at it, never gave in and couldn\'t ask for more, maybe just a bit of quality. We came close. We came in decent form but it was always going to be tough.\"