The third round of the FA Cup may have got underway yesterday evening, but the main bulk of matches will be played over the next four days.

It's a stage of the competition that sees teams from the Premier League and Championship enter the fray, which always brings about some intriguing ties, as well as the real possibility of some shock results.

Here, Sports Mole has picked out five ties that we believe could end in upsets.

Speaking recently to BBC Newcastle, Blyth manager Tom Wade summed up his side's chances of reaching the fourth round perfectly: "We need Birmingham to have a bad day and us to be absolutely superb."

If this fixture were played 100 times, Championship side Birmingham would win 99 of them. However, this is the FA Cup and anything can happen. Northern Premier League outfit Blyth have already beaten Altrincham and League Two's Hartlepool en route to this stage of the competition, which should fill them with plenty of confidence.

Tranmere may be battling to stay in the Football League, but since Micky Adams took over in October, his side has lost just four times. What's more, they have history in the FA Cup, having reached the quarter-finals in 2000, 2001 and 2004 - runs that saw them defeat the likes of Everton and Southampton.

In Swansea, they face one of the Premier League's best footballing sides. Yet, that may count against the Swans on this occasion, particularly if it's wet and windy on the Wirral and the Prenton Park pitch is sticky.

Conference side Dover will probably be fearing 'new manager syndrome' when Palace visit the Crabble Athletic Ground. The Premier League outfit announced the appointment of Alan Pardew earlier today and often a new manager inspires his side to victory.

Pardew's major target, though, is ensuring that the Eagles retain their Premier League status. With that in mind, there could be scope for Dover to take advantage, especially as they will be performing in front of a home crowd. Chris Kinnear's men are in no immediate danger as far as relegation is concerned, so their full concentration should be on this encounter.

Under Nigel Clough's management, United have been cup specialists. This season, the Blades are in the semi-finals of the League Cup, while last term they reached the last four of the FA Cup, before being beaten by Hull City at Wembley. During that run, they defeated the likes of Aston Villa and Fulham.

Meanwhile, similar to Palace, Harry Redknapp's QPR are most concerned with staying in the top flight. That could well be reflected in Redknapp's team selection, with some squad players potentially given a run out at Loftus Road. League One United have capitalised on such circumstances before and they could well do it again.

Although this a Wimbledon side under a different guise, the comparisons between this tie and the 1988 final have been impossible to avoid. On that occasion, the famous Crazy Gang defied the odds to topple Liverpool 1-0 at Wembley.

The gulf in class between the two sides now is even greater than 27 years ago, so surely there will not be a repeat? Of course, if Liverpool were to play well, they will win, but Brendan Rodgers's men have struggled for positive form all season. Again, like many Premier League sides, there may also be some changes to the team, with those on the fringes handed an outing.