The Tunisian 10th seed, runner-up for the last two years, made light work of her world 68th-ranked opponent, breaking her immediately to take a 3-0 lead before each held their serve for the rest of the first set.
Jabeur then cranked up the power a notch in the second set, while simultaneously shutting down the angles as she snuffed out Uchijima's game.
As the game drew to a close the Japanese player, making her first appearance in the main draw in south London, looked skyward a number of times in obvious frustration.
She fended off three match points but finally caved in on the fourth, another thumping Jabeur forehand winner to close out the match.
In a steamroller performance, Jabeur won every single one of her first-serve points and fired in 21 winners to her opponent's nine.
Jabeur next meets American Robin Montgomery, ranked 161 in the world, as she pursues her dream of a Grand Slam triumph.