Middlesbrough will have the weight of history on their side when they line up against Brentford in their play-off semi-final second leg on Friday. As Chief Sports Writer Scott Wilson explains, a first-leg away win has provided a safe passage to Wembley in the past

IN the wake of Friday’s play-off semi-final first leg victory at Brentford, Middlesbrough’s players and coaching staff were queuing up to warn that it would be wrong to take anything for granted ahead of this week’s return game at the Riverside.

‘It’s only half-time’, was the response to Fernando Amorebieta’s stoppage-time winner at Griffin Park, but while the determination to avoid any complacency is understandable, the history books suggest there will be only one outcome on Friday night.

Since the advent of the play-off system in 1987, 14 teams have claimed an away win in the opening leg of a play-off semi-final in the Championship or its equivalent division. All 14 then went on to make the final in the return game.

Middlesbrough’s challenge is to make that tally 15 come the final whistle in three days time, and while there have been a couple of close shaves in the last couple of decades, it is clearly a huge advantage to be defending a lead on home soil at this stage of the play-off process.

The most recent first-leg winners on their travels were Derby County 12 months ago. Steve McClaren’s side recorded exactly the same score as Middlesbrough as Tomasz Kuszczak’s own goal handed them a 2-1 victory at Brighton’s Amex Stadium.

The return at the Ipro Stadium could hardly have been more straight-forward, with Derby scoring first and storming into a four-goal lead before a late Kazenga LuaLua consolation resulted in them winning 6-2 on aggregate.

West Ham were similarly untroubled two years earlier as they followed up a comprehensive 2-0 win at Cardiff with an even more emphatic 3-0 success at Upton Park. A fortnight later, and Ricardo Vaz Te’s winner at Wembley took them back to the top-flight.

Of the 14 sides to have made the most of a first-leg away win, one needed extra-time to scrape through and two needed penalties to reach Wembley.

Cardiff, in 2010, came closest to slipping up as, having won 1-0 at Leicester, they fell 3-1 behind in the return leg in Wales before a second-half penalty from Peter Whittingham took the game into extra-time.

With no goals in the extra period, the game went to spot-kicks, and Cardiff eventually won 4-3, with Mark Kennedy converting the decisive spot kick.

The other first-leg away winners who needed penalties to progress were Derby in 2007. After winning 2-1 at Southampton, the Rams looked to be heading to Wembley when the return game was locked at 2-2 with a minute remaining.

Grzegorz Rasiak’s 89th-minute strike took the game into extra-time, with Derby going on to triumph 4-3 on spot-kicks after former Newcastle striker Leon Best and Inigo Idiakez both missed spot-kicks for Southampton.

Interestingly, the most common scoreline for a first-leg away win in the Championship play-offs is the 2-1 victory that Boro claimed last Friday.

The Teessiders will be the sixth team to defend a 2-1 advantage at home when they line up at the Riverside, and for all that Aitor Karanka will preach the need for caution in the next few days, previous play-off history suggests his side can begin to plan for Wembley after their first-leg success.

WHO HAS CLAIMED A FIRST-LEG AWAY WIN AND GONE ON TO REACH THE CHAMPIONSHIP PLAY-OFF FINAL?

2014

Brighton 1-2 Derby

Derby 4-1 Brighton

(Derby win 6-2 on aggregate)

2012

Cardiff 0-2 West Ham

West Ham 3-0 Cardiff

(West Ham win 5-0 on aggregate)

2010

Leicester 0-1 Cardiff

Cardiff 2-3 Leicester (AET)

(Cardiff win 4-3 on penalties, 3-3 on aggregate)

2008

Crystal Palace 1-2 Bristol City

Bristol City 2-1 Crystal Palace (AET)

(Bristol City won 4-2 on aggregate)

Watford 0-2 Hull

Hull 4-1 Watford

(Hull won 6-1 on aggregate)

2007

Southampton 1-2 Derby

Derby 2-3 Southampton

(Derby win 4-3 on penalties, 4-4 on aggregate)

Wolves 2-3 West Brom

West Brom 1-0 Wolves

(West Brom win 4-2 on aggregate)

2006

Crystal Palace 0-3 Watford

Watford 0-0 Crystal Palace

(Watford win 3-0 on aggregate)

2000

Birmingham 0-4 Barnsley

Barnsley 1-2 Birmingham

(Barnsley win 5-2 on aggregate)

1998

Ipswich 0-1 Charlton

Charlton 1-0 Ipswich

(Charlton win 2-0 on aggregate)

1996

Charlton 1-2 Crystal Palace

Crystal Palace 1-0 Charlton

(Crystal Palace win 3-1 on aggregate)

1995

Tranmere 1-3 Reading

Reading 0-0 Tranmere

(Reading win 3-1 on aggregate)

1990

Blackburn 1-2 Swindon

Swindon 2-1 Blackburn

(Swindon win 4-2 on aggregate)

1988

Blackburn 0-2 Chelsea

Chelsea 4-1 Blackburn

(Chelsea win 6-1 on aggregate)