It's set to be a tantalising encounter at The Stadium of Light tonight, as two former Premier League sides go head to head in the first leg of their League One play-off semi final.

At one point or another over the course of the season, both Sunderland and Portsmouth will have felt they had a strong chance of automatic promotion, but now only one of them will make it to Wembley for a promotion decider with either Charlton or Doncaster and a place in the Championship.

Here, we look at the statistics behind the league meetings this season.

It was Portsmouth who came away with the three points in the first encounter between the two sides, winning 3-1 in an eventful match at Fratton Park in the final match before Christmas.

Pompey took the lead just minutes after half time, when Sunderland's Glenn Loovens was sent off for bringing down a clean through Oli Hawkins inside the area, with Gareth Evans converting the resultant penalty.

Kenny Jackett's side doubled their advantage when Ronan Curtis fired in from a tight angle minutes later, and though Luke O'Nien pulled one back for the ten men, Ben Thompson's deflected shot 18 minutes into the second half secured the points for Portsmouth in front of a sold out Fratton Park.

The reverse fixture at The Stadium of Light took place just under two weeks ago, and ended in a 1-1 draw which clearer didn't do either side's automatic promotion chances any favours.

Tom Flanagan headed The Black Cats in front from an Aiden McGeady free kick inside the opening ten minutes, however Pompey levelled midway through the second period when Jamal Lowe tapped in after Lee Brown's header came back off the crossbar.

The visitors then had a goal disallowed for a foul on Sunderland 'keeper Jon McLaughlin, while at the other end Portsmouth 'keeper Craig MacGillivray saved well from Charlie Wyke and Max Power, before substitute Will Grigg hit the post with just five minutes left on the clock.

Of course just weeks before that encounter at The Stadium of Light, the two sides had met at Wembley in an enthralling CheckaTrade Trophy final, which saw Nathan Thompson's late equaliser for Pompey take the game into extra time after a 1-1 draw in the 90 minutes.

Portsmouth then thought they has won it when Jamal Lowe put them back in front with just five minutes of the extra 30 remaining, but Aiden McGeady scrambled in a late equaliser to take the game to penalties.

Pompey however were not to be denied, with Lee Cattermole the only man to miss his penalty, sealing a 5-4 win in the shootout for Portsmouth.

Therefore, Jackett's side will go into this play-off clash brimming with confidence given what has happened between the two sides already this season, but they must be wary of Sunderland still.

The Black Cats will be desperate to make up for that Wembley disappointment, but first they must ensure they get back to the home of football, and they will feel there is no better way to do so than by beating their conquerors from the last time they were there.