Caolan Lavery’s second-half goal sent Walsall into the FA Cup second round at the expense of National League North club Darlington.
Striker Lavery settled their first-round replay with a powerful near-post header from Rory Holden’s right-wing corner.
The Saddlers will host Oxford United of League One in the second round.
The replay at Blackwell Meadows lacked the drama of the first game between the teams, which ended 2-2 after Darlington netted a 97th-minute equaliser.
The hosts, 14th in the sixth tier, battled hard but struggled to create many clear opportunities against their League Two opponents.
Will Hatfield tested Walsall goalkeeper Liam Roberts with an angled shot early on, but the hosts rarely threatened after Lavery’s opener.
Walsall, who are now four games unbeaten in all competitions after a run of six successive league defeats, scored with their only attempt on target.
Victory over Oxford on 30 November would see them match last season’s run to the third round of the competition.
