Non-league Cambridge City held out against MK Dons to secure a famous draw and a first-round replay at Stadium MK.
Ryan Lowe saw his header cleared off the line and the MK striker should have done better when he later shot over.
City, despite rarely seeing the ball, created chances for Craig Hammond but both efforts found the keeper.
Stephen Gleeson rattled one post with a header before Luke Chadwick struck the other with a drive. But the Southern Premier League side hung on.
With 102 places between the teams on the football pyramid it was no surprise to see the League One Dons dominate possession from the start.
Hammond, who has 17 goals this season, almost supplied an early shock for the Lilywhites, finding space before launching a shot straight at David Martin.
But the hosts had to chase the ball from that point onwards, with Lowe in particular squandering numerous chances to make the visitors' domination count.
Cambridge's centre-half pairing of Lee Chaffey and Dave Theobald personified their side's determination, blocking and clearing almost everything thrown at them.
And when they were beaten, keeper Zac Barrett was on hand to produce a series of memorable stops, including a sublime fingertip save from Lowe.
It was enough to see City through to full-time and earn them not only a pay day in Milton Keynes in 10 days' time, but arguably the greatest result in the club's 104-year history.