Match ends, Valencia 2, Arsenal 4.
Pierre-Emerick Aubameyang's hat-trick for Arsenal set up an all-English Europa League final against Chelsea as they won in Valencia for a 7-3 aggregate victory.
The Gunners are now one win away from Champions League qualification, while manager Unai Emery can make history by winning a record fourth Europa League crown.
Trailing 3-1 from the first leg in London, Kevin Gameiro's close-range effort had given the hosts the early impetus.
However, Aubameyang's right-foot volley from 20 yards levelled matters before Alexandre Lacazette put Arsenal ahead with a placed effort into the right corner.
Gameiro, a four-time winner of the competition at Sevilla and Atletico Madrid, tapped in Valencia's second of the night before Aubameyang rounded off the scoring.
The Gabon forward slid in from Ainsley Maitland-Niles' cross and then blasted emphatically into the top corner late on to complete his hat-trick and a 4-2 win.
It means Arsenal, whose first away game of this Europa League campaign was in Azerbaijan against FK Qarabag, will return to the country to face Maurizio Sarri's side in the final on Wednesday, 29 May (20:00 BST).
It will be the first all-English affair since Tottenham defeated Wolves over two legs in 1972, when the competition was known as the Uefa Cup - and the first time that all four finalists in Europe's top two club competitions have come from one nation.
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Aubameyang and Lacazette strike again
Barring an unlikely combination of final-day results in the Premier League - Arsenal need to win and Tottenham to lose, with the Gunners making up an eight-goal swing in goal difference - Arsenal's Champions League hopes now rest on winning the Europa League.
Portugal, Ukraine, Belarus, France and Italy have been among the destinations that Emery's side have visited, navigating 14 games to reach the final and while they have been unconvincing on occasions, this performance underlined their credentials as potential winners.
Emery, who has earned the tag "Mr Europa League" after winning the competition in 2014, 2015 and 2016 while in charge of Sevilla, was vindicated in his bold team selection.
The deployment of Aubameyang, Lacazette and Mesut Ozil all worked as they recovered from Gameiro's early goal to overcome the intimidating atmosphere inside the Mestalla Stadium.
Ozil's 92% passing accuracy was better than any other Arsenal player when he departed just after the hour mark, while Aubameyang and strike partner Lacazette demonstrated their growing understanding.
Responsible for the Gunners' first-leg lead, the duo again tormented their Spanish opponents throughout. Lacazette's flick-on allowed Aubameyang to race clear and volley in their opening goal, before he swivelled on Lucas Torreira's pass when scoring the visitors' second.
Aubameyang's two late goals brought up 48 goals between them this season, with no other Arsenal player contributing more than six. But Emery's next task is to turn his club into winners in Europe.
While his remarkable record now stretches to 19 unbeaten Europa League knockout ties, Arsenal have lost their last three major European finals - the Champions League final to Barcelona in 2006, the Uefa Cup final to Galatasaray in 2000 and the Cup Winners' Cup final to Real Zaragoza in 1995.
Spirited Valencia run out of ideas
While Valencia had enjoyed a good record against their opponents on the east coast of Spain, it had been 16 years since their last victory over Arsenal, which came in the Champions League.
That was success was heavily indebted to the aerial power of Norway forward John Carew, who scored twice in a 2-1 win.
And at time, the La Liga side may have wished for an alternative route to goal - particularly during the second period when Arsenal's control of the tie appeared complete.
While Gameiro added to his impressive CV in the tournament with poacher's efforts, taking his tally at the Mestalla to 11 goals in his last 12 starts, there was a predictability about Marcelino's side, with which Arsenal's three-man defence got to grips as the game wore on.
Portugal winger Goncalo Guedes, who carried much of their early threat was shackled by Maitland-Niles and eventually withdrawn, as was Rodrigo Moreno, the creator of both Valencia goals.
That left Gameiro without any supply and allowed Arsenal to capitalise at the other end of the pitch.
Man of the match - Pierre-Emerick Aubameyang
'We can be proud of the whole club' - what they said
Arsenal manager Unai Emery told BT Sport: "I am very proud of the players and the supporters. The players did all they could and we can be proud of the whole club."
On his past success in this tournament: "The past is for experience and can be used in the present. It is very difficult to play in finals - we took our opportunity today which we are happy about.
"We knew we had to be calm after they scored and we needed to control our emotions. It is very difficult to score four goals against this team because they are very organised. It gave us confidence to score quickly, we know our strikers are taking chances."
Arsenal forward Pierre-Emerick Aubameyang told BT Sport: "We have learned from last season and this year we didn't make the same mistakes. Now we are through to the final."
On his relationship with Alexandre Lacazette: "We have talked a lot about our relationship and it is a pleasure to play with him, above all when you win games like this."
Arsenal in seventh final - the stats
- Arsenal have qualified for their seventh European final (one Fairs Cup, three Cup Winners' Cups, one Champions League, two Uefa Cup/Europa League), lifting the trophy on only two of the previous six occasions.
- Valencia lost for only the second time in their past 22 home games in all competitions (W15 D5).
- Arsenal won away at Spanish opposition for the first time in eight games (D2 L5), since a 1-0 win at Real Madrid in February 2006.
- Including finals, Arsenal manager Unai Emery has won his last 19 Europa League knockout ties, last being eliminated from the competition in the 2011-12 semi-finals with Valencia.
- Valencia's Kevin Gameiro has been directly involved in 12 goals in his last 12 starts in home Europa League games, scoring 11 and providing an assist for the other one.
- Arsenal's Pierre-Emerick Aubameyang has netted 29 goals in all competitions this season, a haul only Sergio Aguero (31) can better among Premier League players.
- Since his debut in August 2017, Alexandre Lacazette has been directly involved in 51 Arsenal goals in all competitions, more than any other player (36 goals, 15 assists).
- Excluding own goals, 11 of Arsenal's last 12 Europa League goals have involved Lacazette and/or Aubameyang (four goals and one assist for Lacazette; six goals and two assists for Aubameyang).
Arsenal travel to Burnley in their final Premier League game on Sunday 12 May (15:00 BST) before they face Chelsea in the Europa League final in Baku on Wednesday, 29 May (20:00 BST).
- 13Murara Neto
- 21PicciniSubstituted forSolerat 56'minutes
- 24GarayBooked at 38mins
- 5GabrielBooked at 90mins
- 14GayáBooked at 43mins
- 7Gonçalo GuedesSubstituted forTorresat 71'minutes
- 19RodrigoSubstituted forMina Lorenzoat 72'minutes
- 15Latorre Grueso
- 22Mina Lorenzo
- 11TorreiraSubstituted forGuendouziat 80'minutes
- 31KolasinacSubstituted forMustafiat 71'minutes
- 10ÖzilBooked at 62minsSubstituted forMkhitaryanat 62'minutes
- 9LacazetteBooked at 90mins
- Danny Makkelie
- Shots on Target
Gabriel (Valencia) is shown the yellow card.
Alexandre Lacazette (Arsenal) is shown the yellow card.
Second Half ends, Valencia 2, Arsenal 4.
Foul by Daniel Parejo (Valencia).
Pierre-Emerick Aubameyang (Arsenal) wins a free kick in the attacking half.
Goal! Valencia 2, Arsenal 4. Pierre-Emerick Aubameyang (Arsenal) right footed shot from a difficult angle on the right to the top right corner. Assisted by Henrikh Mkhitaryan.
Offside, Valencia. Carlos Soler tries a through ball, but Santi Mina is caught offside.
Foul by Ferrán Torres (Valencia).
Pierre-Emerick Aubameyang (Arsenal) wins a free kick on the right wing.
Corner, Arsenal. Conceded by Ezequiel Garay.
Attempt missed. José Gayá (Valencia) left footed shot from outside the box is close, but misses to the right. Assisted by Francis Coquelin.
Offside, Arsenal. Henrikh Mkhitaryan tries a through ball, but Pierre-Emerick Aubameyang is caught offside.
Substitution, Arsenal. Matteo Guendouzi replaces Lucas Torreira.
Foul by Carlos Soler (Valencia).
Nacho Monreal (Arsenal) wins a free kick in the defensive half.
Attempt blocked. Daniel Parejo (Valencia) left footed shot from outside the box is blocked. Assisted by Santi Mina.
Attempt missed. Carlos Soler (Valencia) right footed shot from outside the box is too high. Assisted by Kevin Gameiro.
Attempt missed. José Gayá (Valencia) left footed shot from outside the box misses to the right following a corner.
Corner, Valencia. Conceded by Sokratis.