Alexis stars as Arsenal's three-man defence excels in win at Palace

LONDON -- Three quick thoughts from Arsenal's 3-2 Premier League win over Crystal Palace at Selhurst Park on Thursday:

1. Sanchez stars as Arsenal win

This should have been a tricky contest for Arsenal -- away at an in-form Crystal Palace side unbeaten in eight matches, who defeated the Gunners here last season and offer a combination of defensive organisation and counterattacking speed. Instead, Arsenal produced a professional, composed performance and fully merited the victory. Most encouragingly, Alexis Sanchez looked back to his best.

Arsenal's opener didn't do justice to their impressive possession play. Midway through the first half, in the aftermath of a set piece, Alexandre Lacazette fizzed a shot at Julian Speroni, who could only palm the ball straight to Shkodran Mustafi, and he converted first time from a tight angle -- a fine finish from any player, let alone a centre-back. But Arsenal had created some good chances in open play, their pass-and-move football a welcome sight following four games of stodgy, slow football aside from a five-minute rally against Liverpool.

After Palace had equalised through Andros Townsend, Sanchez took the game away from the home side with two excellent, and very different, goals that recalled his clinical finishing of the past three seasons. After an hour, when teed up by Lacazette's low backward pass on the edge of the box, he arrowed a fine shot through a defender's leg, and it squeezed into Speroni's near post.

His second was even more impressive. A long pass from Jack Wilshere over the Palace defence was swiftly controlled and dispatched with Sanchez's thigh and right boot, respectively, in one sweeping movement, in a manner that recalled his fellow Chilean striker Marcelo Salas' goal at Wembley against England 20 years ago. Wilshere's performance, and assist, will also please Wenger; the former showed he has the discipline and passing range to play this deep role alongside Granit Xhaka effectively.

Sanchez, though, was the star, although it served as a reminder that we're probably into the final few months of his Arsenal career. If so, the Gunners will miss match-winning contributions like these.

2. Wenger's return to three-man defence pays off

Arsenal's dominance of this first half owed much to their system, which surprisingly featured Wenger returning to a three-man defence.

Last season, Wenger's surprise switch to a three-man defence came after a 3-0 thrashing in this fixture; he stuck with that system throughout last season's run-in and the first few months of this campaign.

He subsequently returned to a four-man defence for the trip to West Ham, a dreadfully dull goalless draw, an unconvincing 1-0 home win over Newcastle and the chaotic 3-3 draw against Liverpool last time out. Those three concessions possibly convinced Wenger to change systems once again; here, he reverted to a back three. Sead Kolasinac returned after a three-game absence, suggesting Wenger sees him exclusively as a wing-back rather than a full-back, while Calum Chambers made his first Premier League start in nearly two years. It was quite a shake-up.

Wenger isn't renowned for assessing the opposition before deciding upon his formation, but this tactical switch worked very nicely against Palace's flat, narrow 4-4-2 system. Wing-backs Kolasinac and, in particular, right-sided Hector Bellerin were given free reign to dominate the flanks, with the latter repeatedly getting himself into dangerous positions without ever playing a truly decisive cut-back. Granted, this opened up space for Wilfried Zaha to drift into and threaten on the break, but Chambers was comfortable moving out wide and tracking him down, with Mustafi the spare man, and Laurent Kosicelny watching Christian Benteke.

More significantly, the system allowed Sanchez and Mesut Ozil to combine more regularly, with Ozil drifting inside from the right flank to play neat interchanges with Sanchez's inside-left positions.

This resulted in Arsenal's best two moves of the first half: Sanchez's excellent through-ball to Ozil forced Speroni into a fine close-range reaction stop, and later another pass from Sanchez found Ozil breaking in behind, but he ran out of space and was off balance when approaching Speroni and played a wayward square ball to no one. But Arsenal's best two players being so regularly involved, and in such close proximity, was certainly a positive for Wenger -- they threatened even before Sanchez's match-winning cameo in the second half.

3. Palace put up a fight

Palace's defeat here came as something of a surprise after their impressive eight-match unbeaten run -- but that, in itself, demonstrates how much manager Roy Hodgson has lifted spirits. Three months ago, Palace would have folded easily. Here, they at least put up a fight.

Which isn't to say they ever looked like winning this contest. They were second best in the opening exchanges, keeping a relatively high line and therefore looking rather prone to balls in behind. A couple of long-range efforts from Yohan Cabaye aside, they rarely threatened Petr Cech at 0-0, with Benteke barely involved.

It took a 1-0 half-time deficit to wake up Palace, and their equaliser came just four minutes into the second period. With Bellerin dragged up toward Jeffrey Schlupp, Zaha dribbled at Chambers, dropped his shoulder and went toward the byline before fizzing in a low ball that was expertly swept into the near post by the onrushing Townsend.

It was, in truth, Palace's first genuine goal-scoring chance and promoted their first real rally. Zaha was the obvious dangerman, slipping in Schlupp on the overlap, and the left-back fired into the side netting. But aside from that five-minute spell, the home supporters had little to shout about until James Tomkins' headed consolation goal in the final minute of normal time.

For all their recent good form, the Eagles remain just a point above the relegation zone; after all, they lost their first seven games, and their unbeaten run was primarily about draws rather than wins.