The home side with the first corner of the game, which comes to nothing.

Colin Coates
Former Crusaders captain on BBC iPlayer

He's very fortunate. Leahy has made a mistake and when Jenkins gets in behind, it looks like he's been caught as he has gone to play the ball. For me, it's a massive let off for Linfield.

A big shout for a spot-kick from Glentoran fans in the North Stand as Jordan Jenkins goes tumbling inside the penalty area following a challenge form Darragh Leahy.

Referee Steven Gregg, instead, waves play on.

It could be a big night for the man in the middle given what's at stake for both teams.

James Teelan, now playing on the right, uses some terrific footwork to beat two Dungannon defenders in the box.

However, the resulting effort is hit tamely at Declan Dunne.

A cracking atmosphere inside Windsor Park, befitting of such an important game.

Linfield captain Kyle McClean gets us underway for a hugely important game in what is quickly developing into a fascinating title race.

The Glens hold the upper hand on their hosts, thanks to a famous win here on Boxing Day and a draw at the Oval back in September.

However, victory for either this evening could have a major bearing on the destination of the Gibson Cup come the end of April.

Portadown are the team on top as the rain begins to fall at Shamrock Park.

Very little in the way of attacking momentum for the visitors so far.

Colin Coates
Former Crusaders captain on BBC iPlayer

Both managers will have an idea of how big this game is but but they will both not want to lose the game. A draw wouldn't rule either of them out of the race but three points would be a huge shot in the arm for either side.

James Teelan looks incredibly lively for Portadown, since coming on he's been a threat on the left-wing.

BBC iPlayer

You can now watch the build-up to the 'Big Two' derby on BBC iPlayer or on the BBC Sport NI website by pressing the 'watch live' button at the top of the page.

Thomas Kane is joined on commentary by former Crusaders and Cliftonville defender Colin Coates.

It always promised to be a big game but, given the events of last night, this latest instalment of the 'Big Two' rivalry has suddenly taken on even greater significance.

Linfield manager David Healy, fresh from Tuesday night's impressive away win at Dungannon Swifts, makes just the one change to his starting line-up as Euan East replaces Sean Brown, who drops to the bench.

Opposite number Declan Devine makes wholesale changes to the team which defeated Drumaness Mills in the Irish Cup during the week.

Out of the squad go Billy Crellin and MJ Kamson-Kamara, while Liam Burt, James Douglas, Ben Gallagher, Dylan Connolly and Josh Daniels are named among the replacements.

In their place come regular starters including goalkeeper Andrew Mills, Ryan Cooney, Jordan Stewart, Aaron McEneff, captain James Singleton and the former Crusaders pair of Jarlath O'Rourke and Ross Clarke.

Linfield: Johns, East, Millar, McClean (c), Hall, Archer, Baird, McGee, Fitzpatrick, Taylor, Leahy.

Subs: Walsh, Gorrin, McKee, Yates, Mulgrew, Frizzell, Brown.

Glentoran: Mills, Cooney, Palmer, Stewart, Larmour, Amos, O'Rourke, Singleton (c), Jenkins, Clarke, McEneff.

Subs: Beimers, Kane, Connolly, Burt, Gallagher, Douglas, Daniels.

Image source, BBC Sport

Great defending on show from Lee Chapman, who forces Kobei Moore to dribble the ball out of play resulting in a Portadown goal-kick.

Portadown are forced into an early change as Josh Ukek comes off for James Teelan.

The first chance of the game goes the way of Shea Gordon.

A cross from the right lands at the feet of the midfielder, but he slices his effort wide.

Referee Michael McKenna whistles to get us started here at Shamrock Park.

Watch highlights as Cliftonville beat Crusaders 5-2 in the north Belfast derby at Solitude.

Philip Major
Sportsound summariser

Crusaders have just been a little bit soft all season. When I look at them I don't think there is enough communication and showing the leadership they need in the position they are in.

Portadown make just one change from the squad which started in Tuesday's abandoned game against Cliftonville.

Lewis MacKinnon returns from suspension and replaces Josh Carson, who drops to the bench.

Rodney McAree makes three changes from the team which suffered a 4-1 defeat to Linfield at Stangmore Park.

Tiernan Kelly, Shea Gordon and Cahal McGinty start in place of Caolan Marron, Kealan Dillon and Leo Alves, with the latter two dropping to the bench.

Portadown: Moore, Altintop, MacKinnon, Wilson, Chapman, Ukek, McCullough (C), Fyfe, Scott, McCartan, Towe.

Subs: Isamala, Gibson, Tetteh, Teelan, Obhakhan, Quinn, Carson.

Dungannon Swifts: Dunne, Scott, Kelly, Glenny, Gordon, McGinty, Doyle, Wallace, Moore, Bigirimana (C), McAllister.

Subs: Henderson, Maguire, Knowles, Dillon, Alves, Mitchell, Smith.

Image source, BBC Sport

Josh Kelly glances home his first goal for Cliftonville to add a late fifth for the Reds at Solitude.

Glenavon claim their first points away from home of the league campaign with a well-deserved success at Clandeboye Park.

After some miserable away days, those Glenavon fans will have a much happier journey back to Lurgan tonight!

The Lurgan Blues are now seven points adrift of 11th placed Crusaders - is the great escape still a possibility?