It’s here.

Leinster’s final hope of putting themselves in with a shout of the last eight.

After back-to-back losses against Clermont in December, many thought it was an impossible feat. But Ireland captains past and present are out to prove the doubters wrong in Exeter today.

The teams are just about to emerge from some tense, shouty dressing rooms. Here are the potential protagonists.

Exeter Chiefs: Luke Arscott; Ian Whitten, Sireli Naqelevuki, Jason Shoemark, Matt Jess; Gareth Steenson, Kevin Barrett; Ben Moon, Neil Clark, Hoani Tui; Tom Hayes (c), Dean Mumm; Tom Johnson, James Scaysbrook, Richard Baxter.

Replacements: Jack Yeandle, Carl Rimmer, Craig Mitchell, James Hanks, Ben White, Will Chudley, Ignacio Mieres, Nic Sestaret.

Leinster: Rob Kearney; Isa Nacewa, Brian O’Driscoll, Gordon D’Arcy, Luke Fitzgerald; Jonathan Sexton, Eoin Reddan; Cian Healy, Richardt Strauss, Mike Ross; Leo Cullen (c), Devin Toner; Kevin McLaughlin, Sean O’Brien, Jamie Heaslip.

Replacements: Sean Cronin, Heinke van der Merwe, Michael Bent, Rhys Ruddock, Shane Jennings, Isaac Boss, Ian Madigan, Fergus McFadden.

Romaine Poite has a quite fetching beard these days, and near those bristles he puts the cool steel of the whistle.

KICK OFF: Steenson drops the ball onto the Leinster 22 and two blues rise. Leo Cullen knocks on and it’s a scrum to the Chiefs.

The drone of the tomahawk chop song rings around Sandy Park, but it doesn’t stop Mike Ross laying down a marker. He wins a penalty, allowing Sexton drill the ball to half way.

Another penalty for Leinster; for offside after the line-out.

Again J-Sex goes for touch and Leinster can set an attack in motion.

TRY! Exeter 0 -7 Leinster (D’Arcy ’4)

The maul quickly turned messy, but Leinster look very, very hungry. Healy and Cullen taking the ball in close contact before Reddan spins the ball to Sexton. His pass finds D’Arcy who crosses the line with a subtle step off his right.

The score is converted too.

Well, if ever Leinster need a perfect start it was today. The belief has just been given reason to grow and Stu Barnes has begun talking about the “miracle” of the 2011 final.

The Chiefs have not been unduly put off by the early score, they look intent on matching fire with fire and there is a ferocious pace to this game.

The men in pink have enjoyed the greater territory since the score and scrum-half Kevin Barrett produced their highlight so far, gaining 20 metres from a sniping run.

The pace of the game has just settled a little. And that’s played into Leinster’s hands as another pink scrum goes backward allowing Reddan get on top of Barrett and force him to kick out on the full.

From the line-out, Leinster set Sean O’Brien barrelling over the gain line. A few phases later Healy and Heaslip do likewise setting up a platform for another move wide.

There, Kearney, attempts a reverse pass for Nacewa stepping inside. The move is well read by the Chiefs and Whitten drags the former Auckland Blue to the ground and forces a penalty.

For those wondering.

TRY! Exeter 7 – 7 Leinster (Clark ’15)

There was never a doubt Exeter would make a game of this. They set up a powerful mal on the left of Leinster’s 22 and and Neil Clark pours through the gap to give Steenson the chance to square the game, which he does with a glorious, curling, high and handsome conversion.

Sean O’Brien has made his fourth carry of the night and a quick stat from Sky tells us he has only failed to break the gain-line with one of those.

Seanie’s back. No doubt about it.

Here come Leinster and again we have a maul on our hands.

After the roll ends, Cian Healy plays the scrum-half and tries to sell a dummy on the blind-side, but nobody buys that guff and he’s just stopped from crossing the line by Tom Hayes.

Reddan shows Healy how to dummy as he peels left off the back of a scrum, before twisting back to the openside… right into Poite, who then has to signal another scrum.

The scrum brings another penalty. Leinster pack down again in search of a penalty try.

The Chiefs, from somewhere, find a power boost and lock the scum.

Leinster have to go through the backs after O’Brien is held up under the posts.

Two magnificent subtle passes from O’Driscoll, then Sexton give Big Bob Kearney a five-metre dive for the line.

TRY: Exeter 7 – 12 Leinster (Kearney ’29)

With nothing to lose, the Chiefs are making this a hell of a game. Dean Mumm carries forward and the Chiefs have a penalty advantage coming.

PENALTY TRY! Exeter 14 – 12 Leinster (’34)

The Chiefs decline the kick for goal and it pays off as Leinster collapse a maul breezing towards the corner and Poite sprints, Alan Shearer style, to the posts.

The try has brought the Tomahawk choppers to their feet and they create another scoring chance .

PENALTY: Exeter 17 – 12 Leinster (Steenson ’39)

HALF TIME: Exeter 17 – 12 Leinster

Sexton attempts to inject one last opportunity into the half with a quick kick-off that bounces nicely into touch by the five-metre line, but the clock goes red soon afterwards and the 30 men bound toward the changing room.

The second half is under way with Sexton kicking to the Chiefs. Sky’s sideline man tells us that Joe Schmidt stormed to Romain Poite to make a point or two at half time, but the Frenchman (in as polite a move as you may expect from a cartoon-ish Frenchman) shut the door in his face.

TRY! Exeter 17 – 19 Leinster (O’Driscoll ’45)

Just the 32nd Heineken Cup try for the centre. He pounced after Leinster took the ball patiently through the phases on the right and a fine offload from Leo Cullen opened up some space for BOD to strike on the left.

The conversion, midway from posts the sideline is no problem for Sexton.

Another Leinster maul close to the try-line, but after it goes to ground the pink shirts pile into the ruck and Poite signals the scrum their way.

Stu Barnes makes a big deal of Ulsterman Gareth Steenson punching the air. Fly-half union.

Leinster’s scrum wins the ball back, they lose it again after Toner carries towards the posts, but Barrett knocks the ball on and Leinster have a scrum for the bonus point here.

TRY: Exeter 17 – 26 Leinster (Heaslip ’53)

Mike Ross wins his personal battle hands down yet again. Heaslip picks the ball up at the base of the tilted scrum with nary a tackler in sight and dives under the posts.

Isaac Boss is in the game. Eoin Reddan is helped off the field looking as though he’s not quite sure where he is.

He may join the Ireland squad with a bit of a headache tomorrow.

The steam just looks to have run out for the hosts as Devin Toner steals a line-out…. but they had a second quarter. Can they do like-wise in the fourth?

This game keeps making attempts at commentary look foolish. Exeter win a penalty on halfway and decline a chance to narrow the gap. They shove the ball into the corner and look to threaten in the maul.

This time though, Leinster prevent any further phases with a fine choke tackle.

Rhys Ruddock is in the game for Kev McLaughlin now.

Neither side can force momentum their way. Sexton sends a bomb of a kick up from that scrum on the 22, but it glides all the way over the dead ball line and the scrum is Exeter’s now in a threatening central area.

The set-piece comes to nothing and Sexton asks Kearney to run from deep. The fullback breaks the line, and Leinster look to build with Boss and Ross carrying into contact, but Sean O’Brien is caught standing with the ball and the Chiefs come away with it.

Another penalty conceded by the visitors in midfield and another superb touch finder from Steenson. They by-pass the maul this time and go straight to their Pacific-islander in midfield. Leinster keep them from crossing into the 22, but Cullen in pinged for holding on.

Steenson goes for the corner again. Standby by for drama.

A 14-man line-out, but the maul doesn’t last and Leinster survive for now.

PENALTY: Exeter 20 – 26 Leinster (Steenson ‘ 70)

This time Hayes asks for a penalty to put the hosts within seven.

Just as the home crowd think Arscott has made a big break in midfield, Baxter is penalised for crossing and it’s Sexton’s turn to kick for the corner.

Cronin’s line-out is lost and back come the Chiefs.

SIN BIN: Ben White walks the walk. Poite finally taking action in a game riddled with penalties as the replacement hangs on in the tackle.

Straight in front of the posts, Sexton wants the points.

PENALTY Exeter 20 – 29 Leinster (Sexton ’74)

Sexton clearly feels his potential future employers can do a job at Thomond Park tomorrow. As things stand a bonus point win will do for Munster unless Leinster get two more tries.

SIN BIN Isaac Boss is gone and this game will end 14 v 14. Four minutes remain.

All week we envisage the end of this game looking like the Chiefs defending the Alamo. Instead, the hosts are piling the pressure on until they cross in midfield and Sexton can clear the penalty up to within 30 metres of the line.

Cian Healy is your SkySports man of the match. Fair call, he’s carried brilliantly and been part of a dominant scrum.

FULL TIME: Exeter 20 – 29 Leinster

The final whistle is greeted by near silence in Devon. Neither side happy with the final outcome. Leinster have got the win and four tries, but….

If Munster can match that at home to a weakened Racing team tomorrow then they will knock Leinster out.

You thing they’d like that kind of thing in Clare, Tipperary, Kerry, Limerick, Cork and Waterford?