Last updated on .From the section FA Cup

AFC Wimbledon, Bristol City, Derby County, Gillingham, Millwall, Newport County, Oldham Athletic.

Already this season, seven clubs from outside the Premier League have knocked clubs from England's highest league out of the FA Cup.

But which teams have been the most prolific giant-killers in FA Cup history?

Using the database from sports analysts Gracenote and a definition of a giant-killing as knocking out a top-flight team when not in the top flight, we discovered the answer ahead of the fifth round commencing on Friday.

Most frequent giant-killers?

The record for the club with the most frequent FA Cup giant-killings was actually equalled in this year's FA Cup fourth round when Millwall won 3-2 against Everton taking their tally to 25 scalps and equalling Southampton's record.

Millwall have been a prolific giant-killer in the past seven seasons of the FA Cup, facing seven Premier League clubs and knocking five of them out and victory this weekend against League One bottom club AFC Wimbledon will give Millwall their third FA Cup quarter-final in the past seven years.

The Lions would probably have preferred a bigger fish than AFC Wimbledon in this year's fifth round though.

Millwall's record against teams playing in a lower division is somewhat less impressive. Southend United (2014), Bradford City (2015) and Rochdale (2018) have all knocked the south Londoners out of the competition in the past seven seasons.

Clubs with the most giant-killings in the FA Cup (Source: Gracenote) Club Total giant-killings Pre-WWII Post WWII Last giant-killing Southampton 25 17 8 2011 v Blackpool Millwall 25 11 14 2019 v Everton Birmingham City 21 2 19 2012 v Wolves West Ham United 20 7 13 2005 v Norwich City Fulham 20 10 10 2017 v Hull City Sheffield United 20 4 16 2015 v Queens Park Rangers

League Two clubs rarely make it this far

Fourth tier clubs knocking out most teams from the top two divisions (Source: Gracenote) Club Teams they have knocked out Last victim Peterborough United 5 Colchester United 2008 Newport County 5 Middlesbrough 2019 Aldershot Town 4 Oxford United 1987 Scunthorpe United 4 Burnley 2001 York City 4 Grimsby Town 2002 Blackpool 4 Barnsley 2017

The other big giant-killing story of this season is Newport County's run to the fifth round.

Only seven teams from the fourth tier of English football have made it this far in the FA Cup in the 27 years since the Premier League began in 1992-93. Newport are the latest to achieve this but have had to do it the hard way by eliminating Premier League club Leicester City and Championship side Middlesbrough.

This makes Newport only the fifth club from the fourth tier to knock out two teams from the top two divisions in an FA Cup season - the Welsh club are preceded by Southport (1966), Peterborough United (1986), Rochdale (2003) and Crawley Town (2012).

Middlesbrough became the fifth club from England's top two divisions to be knocked out by a Newport County team playing in the fourth tier and Newport thereby joined Peterborough United as League Two teams with the most FA Cup successes against clubs from the top two English leagues.

Only four clubs have ever reached the sixth round while playing in the fourth tier. Cambridge United in 1990 are the most recent, with Oxford United (1964), Colchester United (1971) and Bradford City (1976) the others.

Fourth-tier clubs in the FA Cup fifth round - Premier League era (Source: Gracenote) Club Year in the fifth round Opponent Result Newport County 2019 Manchester City TBD Coventry City 2018 Brighton Lost 1-3 Crawley Town 2012 Stoke City Lost 0-2 Notts County 2010 Fulham Lost 0-4 Swansea City 2004 Tranmere Rovers Lost 1-2 Rochdale 2003 Wolves Lost 1-3 Cheltenham Town 2002 West Bromwich Albion Lost 0-1

Premier League clubs make up less than half of last 16

Only seven Premier League teams have made it to the fifth round of this season's FA Cup, the lowest number for six years.

The record low for the Premier League era is six in 2007-08 when Portsmouth and Cardiff City went on to meet in the only final since 1984 not to feature a team from the current Premier League's 'big six' - Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham.

This season is the 13th since the current FA Cup format began in 1925-26 in which fewer than half of the fifth round clubs are from the top flight, with the lowest number of top-flight clubs reaching this stage five in 1958.

In that year, only Bolton Wanderers, Manchester United, Sheffield Wednesday, West Bromwich Albion and Wolves represented England's top division in the fifth round.

Bolton Wanderers and Manchester United reached the final with Bolton winning 2-0, a little over three months after United had lost much of their team in the Munich air disaster.