MAIN MAN MARTINELLI
Fresh from his brace against Nottingham Forest in the Carabao Cup third round last month, Gabriel Martinelli showed his prowess as a centre forward with two more goals here.
Signed primarily as a left winger, he was used centrally again tonight – as he was against Forest – and both goals bore the hallmarks of a traditional No 9.
His first was a superb header from Kieran Tierney's whipped in cross, in front of the near post. Just 131 seconds he got his second, and fourth in his nascent Gunners career. Reiss Nelson found him inside the area this time, and the 18-year-old Brazilian showed great composure to shift the ball onto his right foot before rifling into the corner.
He was desperate to complete his hat-trick after the break, and came agonisingly close on several occasions. There was no third goal, but he did claim an assist for the fourth goal, laying the ball on a plate for Dani Ceballos under the crossbar.
But he did the damage with his early two goals. Fast starts are what we have been about in the Europa League at the Emirates, we have scored in the opening 20 minutes of each of our last six home games in the competition.
Hector Bellerin was confirmed as part of the leadership team last week, and he didn't have long to wait for his first chance to wear the armband.
Installed by Unai Emery as third captain this season, the full-back took the armband for the first time in his Gunners career with both Granit Xhaka and Pierre-Emerick Aubameyang among the subs.
It was the perfect way for Hector to mark his return to the starting lineup. This was his first start since injuring his ACL against Chelsea back on January 19, and he showed signs he is returning to his old self during a comfortable 90 minutes.
Although still only 24, he is one of the most experienced members of this squad, with more than 180 first-team appearances since making his debut in 2013, and he looks like he will relish leading this side when given the chance.
But tonight was about gaining more fitness, following on from his 90 minutes for the under-23s against Liverpool last Saturday.
His first start back in the Premier League can't be far away.
'CUP TEAM' TAKES SHAPE
This was a much-changed team from Monday's draw at Old Trafford – only Lucas Torreira started both games – but the side gelled from the first whistle, and grew as a unit as the game went on.
Many of these players featured in the 3-0 win over Eintracht Frankfurt on Matchday One, and again as we saw off Forest 4-0 in the Carabao Cup. Three games, three wins, 11 goals scored and none conceded.
The midfield worked especially well tonight, with Dani Ceballos again starring. He made 99 passes, with a 94 per cent competition rate, and took 124 touches in all, more than any other player on the pitch.
He fully deserved to cap the performance with his first goal for the club. Alongside him Joe Willock also gave another performance of great maturity - his driving runs through the midfield are fast becoming something of a trademark.
Further forward it was interesting to see Ainsley Maitland-Niles employed in a more advanced role.
He has made no secret of the fact that defence is not his preferred position, even though he did a sterling job of filling in for Bellerin during the Spaniard's lengthy lay off.
He was given a rare chance to show what he could do further up the pitch by Unai Emery tonight, starting as the right-sided forward in a 4-2-3-1 formation. He showed enough to suggest the head coach has another attacking option at his disposal.
Our starting line-up had an average age of just 22 years and 350 days; the second youngest we have ever fielded in European football.
Bukayo Saka has already shown that these cup games can prove the gateway to Premier League action – and many of those on display this evening will also feel they are ready for increased involvement in the league.
A THREAT FROM THE LEFT
Kieran Tierney made just his second appearance after his summer switch from Celtic, but already the signs are very promising from the Scotland full back.
It was his cross that set up the opening goal, and his delivery from the left flank was on the money all night. He put in seven crosses in all during the match - at least two more than any other player on the pitch – and created four goalscoring chances.
He also excelled at the back, making three tackles and two interceptions - nobody in an Arsenal shirt made more.
Carabao Cup and Europa League tests passed with flying colours - next challenge, the Premier League.
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