Postpublished at 19:29 British Summer Time 8 May 2015
Two strikers have dominated much of the build-up to tonight's game...
Amorebieta scores late winner for Boro
Jelle Vossen header put Boro ahead
Andre Gray levelled after Konstantopoulos error
Second leg on 15 May
Phil Harlow
Two strikers have dominated much of the build-up to tonight's game...
Rob Stevens
BBC Sport at Griffin Park
"Middlesbrough narrowly missed out on automatic promotion but Aitor Karanka has prepared his squad for this tie with a training camp in Spain.
"Boro have had two play-off campaigns in the second tier, beating Chelsea over two legs to win promotion in 1988 but losing at the semi-final stage in 1991.
"The visitors, who have not played in the Premier League since 2009, won both meetings between the two sides this season."
Brentford and Middlesbrough want to get out of the Championship - what about the teams that are desperate to get into it?
The League One play-offs began last night, and both Preston North End and Swindon Town are strong favourites to reach Wembley after winning the away legs of their respective semi-final ties.
Preston won 1-0 at Chesterfield with an early goal from Jermaine Beckford, while Swindon came from 1-0 down and recovered from a first-half penalty miss to win 2-1 at Bramall Lane.
For Brentford boss Mark Warburton, tonight will be his final match in charge at Griffin Park, with the club announcing in February that he will leave at the end of the season.
"The board have made a decision and we recognise that," Warburton, who could take the Bees to the top flight for the first time since 1947, told BBC London 94.9. "It is a frustration but the overriding emotion for me - the same as the players - is to relish the opportunity.
"The table doesn't lie after 46 matches but now we're in this position we're not here to make up the numbers. We have to maximise this opportunity and see how far we can go."
It's been a crazy season in the Championship. Promotion parties, points deductions and pitch invasions - we've had it all.
Now it's the play-offs, which promise to be packed with drama. They never usually disappoint, and this season should be no exception.
So which team will prevail - Norwich City, Middlesbrough, Brentford or Ipswich Town?
BBC Sport looks at the form, facts and prospects of all four Premier League hopefuls.
The end-of-season holiday to Marbella may seem a bit more Sunday league social than Championship, but Middlesbrough's players have enjoyed a spell in the Spanish sunshine ahead of tonight's game.
Boss Aitor Karanka took his squad to Marbella, external for a training camp and, by the sounds of things, we're definitely talking professional preparation, not pub crawl pandemonium.
"Every single exercise was to prepare us to win and every exercise was thinking about Brentford and their style," Karanka told the Teesside Gazette., external
BBC Sport
Two games down, 13 games to go in this season's Football League play-offs.
BBC Sport will be providing a live text commentary of every single play-off game - whether it's in the Championship, League One or League Two - including all three finals at Wembley on 23-25 May.
One league place separated the two sides at the end of the Championship campaign, but Boro were eight points clear of fifth-placed Brentford after beating the Bees twice this season.
In fact, you have to go back to January 1964 for Brentford's last victory over Middlesbrough - a 2-1 win in the FA Cup - and to December 1938 for their last league win over the Teessiders.
To be fair to Brentford, the teams have only met five times since the '60s...
How do you see these Championship play-offs going, then? Which team will claim that precious Premier League place at Wembley on 25 May?
We asked for your thoughts on Sportsday earlier - here's a flavour of what some of you had to say...
Giannina Caraceni: I can see Ipswich nabbing that PL spot. They've got Freddie Sears, and Norwich have recent PL wounds unhealed.
Gavin Vargas: Brentford. Pub on each corner of their ground and makes a joke of Warburton going.
Philip Taylor: I hope Boro come up. Would be great to see the three north east teams in the Premier League.
Matthew Hillary: Norwich v Middlesbrough final. Hopefully with Norwich returning to top flight. Hard derby to come, but been strong for last half of season.
Any more for any more? Get in touch via the BBC Sport Facebook page or by using #bbcfootball on Twitter.
There were a few worries over Patrick Bamford's fitness, but the Championship's Player of the Year starts up front for visitors Middlesbrough.
As for the home side, Brentford name an unchanged team from the one that beat Wigan on the final day of the campaign to secure a play-off place.
Brentford: Button, Odubajo, Dean, Tarkowski, Bidwell, Diagouraga, Douglas (c), Jota, Pritchard, Judge, Gray.
Subs: Macleod, Craig, McCormack, Dallas, Bonham, Toral, Smith.
Middlesbrough: Konstantopoulos, Whitehead, Gibson, Ayala, Friend, Leadbitter (c), Clayton, Adomah, Tomlin, Vossen, Bamford.
Subs: Ripley, Forshaw, Amorebieta, Nsue, Omeruo, Reach, Kike.
Friday 8 May, 2015.
For many, it's been a day of confounded expectations, frayed nerves, unbearable tension, raw emotion, shock results and new beginnings. And now for some more of the same...