If it was an indignity for Arsenal to enter the Carabao Cup at this early stage because of their absence from European competition, they booked their passage to the next round by showing true class. Against a Championship club’s reserves, admittedly, but this was a demonstration from which Mikel Arteta and his team can take heart. Pierre-Emerick Aubameyang scored a hat-trick on his first start of the season, and Nicolas Pépé, Bukayo Saka and Alexandre Lacazette also netted in a match in which the visitors threatened to score nearly every time they attacked. Now all they have to do is play like this regularly against stronger opponents. Then trust will grow in Arsenal’s players and Arteta’s process. Martin Ødegaard and Mikel Arteta. Mikel Arteta admits turning Arsenal’s form around will ‘take some time’ Read more Aubameyang’s performance was one of many positives for Arteta. The club captain had scored only once for Arsenal since being dropped for the north London derby in March and his preparation for this season was disrupted by illness, but here he was sharp and dynamic. “The goals will be great for his confidence,” said Arteta, who praised the striker’s all-round influence. “I said the leadership has to come from the senior players, along with the solutions, and the rest have to complement that with the energy and passion they bring – tonight was a good example.” Other big plus points for Arsenal were Saka’s brilliance and some delicious touches from Martin Ødegaard on his first appearance since his permanent transfer from Real Madrid. Aaron Ramsdale was not particularly busy on his debut but did what he had to do well. Valérien Ismaël’s line-up ensured Arteta would have no excuses, as West Brom’s manager fielded a shadow side, omitting all the players who began their last Championship match and giving debuts to nine youngsters. “It’s clear our priority is the Championship,” explained the Frenchman, unapologetic after West Brom’s record defeat in this competition. Arsenal quickly found out that West Brom’s second string were intent on implementing the ultra-offensive style preached by Ismaël, with frenetic pressing and moves more direct than any seen here under Sam Allardyce last season. Quevin Castro, nifty but a trifle too eager, was booked in the second minute for catching Ødegaard, and Ramsdale was rushed into a pair of uncomfortable early clearances. Soon the goalkeeper had to make his first save, plunging to his right to tip away a low curling effort by the nimble Tom Fellows. West Brom caught Arsenal out with a clever routine from the ensuing corner, but Adam Reach sidefooted wide from seven yards. Aaron Ramsdale made his full debut for Arsenal. Aaron Ramsdale made his full debut for Arsenal. Photograph: Andrew Boyers/Action Images/Reuters Advertisement Arsenal did not wilt. Their passing was more intricate than the hosts but they could only make that matter if they matched West Brom’s energy – which they mostly did. Then they took over. Their first goal came from pressing by their classiest performer, Saka dispossessing Castro outside the West Brom box before shrugging off another challenge and unloading a shot that Alex Palmer could only parry. Aubameyang swept the rebound into the net from close range. Ødegaard could have made it 2-0 after another shot by Saka was blocked but, from an inconvenient angle, the Norwegian struck his shot against the post. Mohamed Elyounoussi (second right) celebrates with Southampton teammates Mohamed Elyounoussi’s hat-trick seals Southampton’s rout of Newport Read more Arsenal quashed their hosts’ resistance before the break with two goals in two minutes. Aubameyang made it 2-0 by tapping in another rebound, this time after Pépé fired against the post after being sent through by Mohamed Elneny. Palmer denied Aubameyang a hat-trick moments later after more sharp play by Saka, but the Gabonese striker acrobatically put the rebound into the path of Pépé, who nudged it into the net. Arsenal’s hunger was unsated. They extended their lead four minutes after the resumption with a wonderful goal. Saka skittered down the left before cutting in-field and feeding Ødegaard and continuing his run. Ødegaard returned the ball to him with a delicious reverse flick, and Saka finished emphatically. Aubameyang produced an even better finish to complete his hat-trick. After Ainsley Maitland-Niles gave him the ball at the left-hand corner of the box, the striker curled an elegant shot beyond the keeper and into the far corner of the net. Arsenal kept coming. Pépé sent a lob on to the crossbar after being released by the substitute Lacazette. One minute later Pépé turned provider and Lacazette showed him how to finish, lashing a low shot into the net from 12 yards.