Alexis Sanchez helped Arsenal to victory over Crystal Palace at Selhurst Park on Thursday, though Palace boss Roy Hodgson will have been pleased with his side's battling display. Palace went into the game looking to extend their eight-game unbeaten run in the Premier League and whilst they put in a spirited performance, they fell to a narrow defeat on a landmark night for Arsenal boss Arsene Wenger.Arsenal dominated the ball in the opening exchanges but they were unable to create any real openings. Granit Xhaka and Yohan Cabaye exchanged efforts from range, before the former saw a low effort hacked away following a cut-back from the left. Wilshere was the next to threaten with a low drive before Arsenal took the lead with 25 minutes on the clock. Palace failed to clear an Arsenal free kick and the ball fell nicely for Alexandre Lacazette to try his luck on goal.He hit a powerful effort towards the far corner and while Julian Speroni in the home goal managed to keep it out, he could only push the ball into the path of Shkodran Mustafi who tapped into an empty net. Arsenal continued to dominate at the point, with Speroni making a fine stop to deny Mesut Ozil after he was put in by a sublime pass from Alexis Sanchez.Wilfried Zaha faded an effort just wide of the far post as Palace briefly threatened a response before Arsenal took control again, going close when Lacazette wriggled away from three men on the edge of the box before fizzing an effort wide. Arsenal could have extended their lead further just before the break as Ozil’s superb touch put him in but he tried to find a team-mate rather than going himself and the chance was lost.The visitors were made to do with a one-goal lead at the break and they looked like they may come to regret that in the second half as Palace raced out of the blocks. The hosts looked like a team transformed and were soon level, with Andros Townsend sweeping home after fine work from Zaha down the left.Jeffrey Schlupp almost completed a shock turn around when he fired into the side-netting but the pendulum of the game swung once against just after the hour mark as Arsenal took the game away from the hosts with two quick-fire goals.The first came as Lacazette found Sanchez in the box with a cute reverse pass, with the Chilean doing the rest as he powered an effort through the legs of a defender and past Speroni. Sanchez was at it again minutes later, though he owed a lot to Jack Wilshere, who played a superb ball over the top for his team-mate to control and slot home from 12 yards.With that, the game had gone for the hosts, though manager Roy Hodgson will have been encouraged by his side’s fighting spirit as they piled forward late on, claiming a late consolation as James Tomkins headed home Townsend's corner. The defeat ends Palace’s eight-game unbeaten run in the Premier League, whilst Arsenal go level on points with north London rivals Spurs.