John Hartson
Former Arsenal striker on BBC Radio 5 live

"Arsenal would like a second to take the pressure off, while it is 1-0, the opposition are always very much in the game."

Image source, Reuters

Iwobi is involved again, producing a lovely back heel to free up Danny Welbeck in the box. It is a tight angle and Mesut Ozil has found space at the back post but the striker shoots and his effort is easily saved by Wayne Hennessey.

Arsenal come forward again but after Hector Bellerin is found out right by Alex Iwobi, his low cross is cut out and put behind.

The resulting corner is played short and worked to Francis Coquelin, whose chipped cross is headed wide by Iwobi. Should have scored.

Arsenal have come out meaning business. They are moving the ball much quicker. Only a misplaced Ozil pass ends a promising move following a period of prolonged pressure on the edge of the Palace box.

Image source, Getty Images

Panic at the back for Palace as Sanchez finds Welbeck and his shot gets caught under the feet of a blocking tackle before being hacked behind. Palace do a better job of clearing the corner.

This is how Alan Pardew thinks he can get his side back into this... Mile Jedinak is off and Bakary Sako is on. The second half is under way.

While they may not have created much, Arsenal do have the lead. And that poses a huge problem for Palace, who barely set foot in the Gunners half in that first 45 minutes. I'm not sure how Alan Pardew changes things now to start fashioning the chances his side might need to get level. But that's why he's currently talking to real professional players in a dressing room and I let my assistant do my team-talks on Football Manager.

The goal somewhat masks the problem, but with this much possession you really should be carving out more chances than Arsenal managed in that half...

Image source, Opta

John Hartson
Former Arsenal striker on BBC Radio 5 live

"It is an absolute brilliant pass from Danny Welbeck, a dink of a pass with his toe. Alexis Sanchez times his run perfectly and heads it over Wayne Hennessey, who is about 6ft 4in and he lobs him from the penalty spot. It was a moment of class.

"Arsenal never had any serious efforts, Hennessey had had a quiet but they were undone by a brilliant pass from Welbeck. Arsenal have a deserved lead."

It took the Gunners 43 minutes to test Wayne Hennessey but they have managed to seize the lead right at the end of a half in which they had nearly 80% of possession.

Image source, Getty Images

The ball is swung into the box and met by Connor Wickham, but he cannot steer his header on target. Gabriel felt he was fouled by the forward, but he was just out-muscled.

Palace have a free-kick right at the end of the half. It would be a very good time to score...

No, they're not. Wayne Hennessey is drawn into action as Mesut Ozil bursts into the box to meet a Sanchez pass and flick a shot towards goal, that the keeper blocks. Comfortably the Gunners' best chance.

Image source, AP

Alexis Sanchez takes it.... wide, via a deflection.

The corner is initially headed away and the delivered back in for Alexis Sanchez at the back post but Joel ward does just enough, trapping the ball between his legs before getting it away.

Arsenal keep coming but the assault is ended when Scott Dann is caught by Gabriel in the box for a free-kick. Are Arsenal going to go the whole half without a shot on target?

Image source, Getty Images

Danny Welbeck raises the volume with a good run that is only ended by a foul on the edge of the box. Now this is a chance for Arsenal to test Wayne Hennessey...

Now Palace have a corner. This could be their best bet of nicking something. Jason Puncheon swings it in but a foul on Petr Cech by Joe Ledley ends the threat.

Another Arsenal corner. Mesut Ozil chips it to the near post, where it is met by Laurent Koscielny but he cannot quite steer his header finely enough to get it on target.

Image source, Reuters

Alexis Sanchez's control lets him down at the crucial moment as Nacho Monreal's cross from the left falls at his feet in the box.

Soon after, Ozil finds Sanchez down the right but his pull-back is into space in the box and Palace can clear.

An encouraging upping of the pace by the home side.