A stunning long-range goal by Vitinha pushed aside non-league Chorley but it was a disappointing performance for Premier league Wolverhampton Wanderers.
Vitinha, on loan from Porto, unleashed a swerving shot from 30 metres past Chorley's Matthew Unwin in the 12th minute -- the only shot Wolves managed on target in their FA Cup fourth round tie.
Apart from that moment of quality it was hard to believe that Wolves, 14th in the Premier League, began the game 111 places higher up the English soccer pyramid than their hosts.
Wolves scraped into the FA Cup fifth round courtesy of Vitinha's sublime strike but they were also fortunate to avoid an embarrassing upset.
Wolves keeper John Ruddy had to make several good saves before they secured a last 16 tie against Southampton or Arsenal.
Having beaten Wigan, Peterborough and Derby, National League North Chorley were enjoying their best ever FA Cup run and they gave Wolves a real scare as well.
They almost snatched the lead when Harry Cardwell picked out Elliot Newby's run into the Wolves area and he chested down for a low shot that Ruddy smothered.
Connor Hall, who scored in the first, second and third rounds for Chorley, threatened an equaliser when his header forced Ruddy to save early in the second half.
Wolves were struggling to keep Chorley at bay and Ruddy had to tip over Andy Halls' header before the plucky underdogs eventually ran out of steam.
Nuno made six changes from last weekend's loss to local rivals West Bromwich Albion, but still included the likes of Conor Coady, Joao Moutinho and £35 million pre-season signing Fabio Silva.
Reflecting the huge divide between the teams, Chorley captain Scott Leather booked the day off from his job as a lift engineer to play for the part-timers.
Many of his team-mates spent the day at work, including their manager Jamie Vermiglio, who is a primary school headteacher.
