Following the Foxes’ 1-0 loss to Liverpool on Sunday, Wilfred Ndidi’s club was humiliated by being demoted from the Premier League to the EFL Championship with Leicester City.
In his 24th game, the Nigerian international has contributed four assists to the Foxes’ current campaign.
At King Power Stadium, the Reds controlled the game but had a custodian in outstanding form in Mads Hermansen.
However, Alexander-Arnold, who had just replaced Conor Bradley, scored about 14 minutes from time.
If Arsenal loses to Crystal Palace in the middle of the week, Liverpool will be declared the winners.
If not, Arne Slot’s team will be content with a victory over Tottenham Hotspur at home the next Saturday.
With 66 points from 33 games, Liverpool leads Arsenal by 79 points.
Leicester has 18 points and is no longer able to reach 17th-place West Ham after losing nine straight home league games without scoring, which is an English record.