Portsmouth sneaked into the FA Cup quarter-finals after an own-goal by Preston's Darren Carter.
Premier League Portsmouth sneaked into the FA Cup quarter-finals on Sunday after an own-goal in the third minute of stoppage time by Preston defender Darren Carter secured a 1-0 victory at Deepdale.
England goalkeeper David James had earlier kept Portsmouth in the Cup with two superb second-half saves, including one from a penalty.
In Sunday's other fifth round tie, Pompey's top-flight rivals Middlesbrough were forced into a replay after a goalless draw away to Championship side Sheffield United.
That looked like being the outcome for Pompey against Championship strugglers Preston until Carter put through his own goal as he tried to clear a corner which had appeared to be handled, albeit accidentally, by Portsmouth's Hermann Hreidarsson.
"The Cup's about winning, however you do it, whenever you do it, the last minute is fine for us," James said.
Portsmouth, tipped by some pundits to end the 13-year monopoly on the FA Cup enjoyed by Chelsea, Manchester United, Arsenal and Liverpool, failed to make the most of their first-half chances.
They were almost made to pay dearly by a side battling to avoid relegation to the third-tier of English football.
On the hour mark, defender Sylvain Distin clipped Preston's Billy Jones inside the box and the home side had a penalty.
But James, guessing correctly, dived to his right to block Simon Whaley's spot-kick.
It was not the first time this season the in-form 37-year-old James had played a key role in a win for the south coast club, who last lifted the FA Cup way back in 1939.
"When they got the penalty, you were quietly confident he was going to save it, he's that good," said Portsmouth manager Harry Redknapp. "You wouldn't want anybody else in the goal at that time but him.
"I thought whoever is taking this is going to be looking at David James knowing he's got a real job on their hands to beat him and that's how it turned out. He's fantastic."
Then Preston substitute Neil Mellor, like James a former Liverpool player, saw the England No 1 athletically save his well-struck curling shot.
Redknapp admitted his team had been fortunate to escape a replay against a Preston side that belied their league position.
"They didn't deserve to lose that game. If they played like that every week they wouldn't be in a relegation battle."
At Bramall Lane, Sheffield United striker James Beattie hit the outside of the post for the hosts just before half-time with a free-kick from the edge of the box.
Boro almost won the game in stoppage time when defender Emanuel Pogatetz's close-range header was blocked in what was Kevin Blackwell's first match as Sheffield United manager following his appointment as successor to Bryan Robson.
"We've got to believe in ourselves. There's a decent set of players here, it's a terrific stadium, a great crowd, there's plenty to build on," said Blackwell.
Sunday's results meant that four clubs from the Premier League (Middlesbrough, Chelsea, Manchester United and Portsmouth), four from the second-tier Championship (West Brom, Barnsley, Cardiff and Sheffield United) and one from third division League One (Bristol Rovers) would feature in Monday's quarter-final draw.
Barnsley made it through on Saturday courtesy of a dramatic 2-1 victory away to five-times European champions Liverpool, coming from behind at Anfield to score the winner with virtually the last kick of the game.
Holders Chelsea beat Huddersfield 3-1 while Manchester United, last season's beaten finalists, thrashed Premier League leaders Arsenal 4-0 at Old Trafford.
Bristol Rovers, the lowest-ranked club left in the draw, enjoyed a 1-0 win at home to Championship Southampton.
Cardiff reached the quarter-finals for the first time since they won the Cup in 1927, with a 2-0 victory against Wolves while, in Saturday's other all-Championship clash, West Brom overpowered Coventry 5-0.