The England international latched onto a ball that was weakly cleared by the Villa defense and lashed a low, first-time shot past unsighted goalkeeper Emiliano Martinez from the edge of the area in the 30th minute.
Arsenal — missing first-choice goalkeeper Aaron Ramsdale because of injury and in-form winger Gabriel Martinelli because of illness — was in control for most of the lunchtime game at Villa Park despite the short turnaround from its loss to Liverpool on Wednesday night.
Saka was a constant danger and his well-taken goal took him to nine in the league this season, during which he has established himself as regular on the right wing, reports AP.
Arsenal moved four points clear of fifth-place Manchester United and within five of third-place Chelsea in its bid to return to the Champions League. This season is the first in a quarter of a century that Arsenal has not been involved in European competition.