Alexander-Arnold showed what he is about with a wonderful assist to bring Liverpool within two points of the top four in the Premier League
It's all in the timing, the control of the ball and the precision swing. Like a glorious golf shot, the perfect cross in football is beyond many players, but Trent Alexander-Arnold strikes the football with such pace, whip and dip that it's no wonder he celebrated Liverpool's opener against Arsenal as though he had headed the ball into the goal himself. (More Football News)
It's The Masters next week at Augusta.
This Emirates Stadium clash was a reminder of last season's Premier League masters in full flow, or at least that was the case for the final half an hour, because the first 60 minutes was so drab the tape should be wiped forthwith and we'll never discuss it again. Arsenal's players, thumped 3-0, would want the whole game deleted from memory, given they were abject from first whistle to last.
Alexander-Arnold had been lively enough before the breakthrough came, and James Milner owed him a better finish from the precise cutback that reached the veteran Liverpool midfielder in the 35th minute. Milner shot wide of the left post.
But in a game between two sides whose seasons have fallen well short of expectations, it was a flash of wonder that reminded the visitors how they became champions with 99 points last term. Gareth Southgate dropped Alexander-Arnold from his England squad a fortnight ago, so this will inevitably be interpreted as some sort of response.
But really it was just Alexander-Arnold doing Alexander-Arnold things. He makes chances and he makes goals, handy attributes for a right-back. And when there is very little actual defending to be done, as was the case against a dreadful Arsenal side, Alexander-Arnold is a world beater.
Diogo Jota, the player on the end of that game-changing cross on Saturday, later described the delivery as "unreal". Jurgen Klopp, who was stunned by the full-back's international omission, said that he "showed his class again".
When all is not going to plan for the 22-year-old, possessing strong defensive cover can paper over his weaknesses, and with Liverpool having hit upon an injury crisis at the back this season, Alexander-Arnold has been unable to count on Virgil van Dijk, Joel Matip or Joe Gomez getting him out of trouble.
So the impact of his handful of errors has been magnified, and the scrutiny reached its apex when Southgate decided he should miss those opening World Cup qualifiers.
Since the beginning of last season, Alexander-Arnold has created 172 chances across all club competitions and had 21 assists. On each count, those are the highest number among defenders in Europe's top five leagues. In the same period, he has made four errors that have led to shots and two that have cost Liverpool goals. Some would accept that ratio.
Gary Lineker, who knows a thing or two about being on the end of crosses for England, believes Southgate got it wrong in dropping Alexander-Arnold.
"The perfect response from @TrentAA to his bizarre omission from the @England squad," Lineker wrote on Twitter on Saturday night. "He's been brilliant tonight. Can't be left at home in the summer. Just can't be."
The Euro 2020 finals surely do beckon for Alexander-Arnold, with England's group rivals Croatia, Czech Republic and Scotland certain to be delighted if he stays at home.
Jota gave Alexander-Arnold a target after coming off the bench just after the hour mark, and the sublime cross from the right that found the striker on the edge of the six-yard box was a striker's dream.
Liverpool are still chasing fourth place, with Chelsea's defeat to West Brom earlier in the day a major boon to the Reds.
Mohamed Salah and Jota, with his second, finished off a lousy Arsenal who had just three goal attempts across the 90 minutes, and Mikel Arteta's men can now be counted out of the race for Champions League places.
Gary Neville, commentating for Sky Sports, condemned a "real flaky performance" by Arsenal, adding: "It's the worst I've seen them for a bit."
Alexandre Lacazette, Pierre-Emerick Aubameyang, Nicolas Pepe and Martin Odegaard all started for the hosts, and Pepe was the only one of the quartet to manage a shot.
Former Liverpool midfielder Jamie Redknapp said Arsenal's display was "putrid", and Arteta would probably agree. This was their heaviest defeat at home against Liverpool in the league.
On the day Liverpool's reign as Premier League champions effectively ended – they cannot possibly catch Manchester City now this season – this was a reminder of how Klopp's men can roll over feeble opposition.
On they go now, to face Real Madrid in the Champions League on Tuesday. The Spanish champions will know all about Alexander-Arnold, who would have made a phenomenal complement to Roberto Carlos back in the day. Now they simply have to stop him.