Match ends, Eintracht Frankfurt 1, Chelsea 1.
Pedro scored an away goal as Chelsea recovered from an early setback against Eintracht Frankfurt to set up an exciting Europa League semi-final return leg at Stamford Bridge.
Eintracht took the lead through their top scorer Luka Jovic, who superbly steered in Filip Kostic's ball.
The Blues, who started with Eden Hazard on the bench, equalised when Pedro thrashed home just before half-time.
David Luiz also went close when his dipping free-kick came off the bar.
The draw means that Chelsea become the first team to go 16 successive Europa League matches without defeat, breaking the record set by Atletico Madrid from 2011 to 2012. They will have the chance to make it 17 in next Thursday's second leg.
Did leaving Hazard on the bench pay off?
There was a great deal of surprise when the Chelsea teamsheet showed Hazard's name among the substitutes.
Manager Maurizio Sarri told BT Sport that he rested his 19-goal forward because of fixture congestion, with the Belgian having played 10 matches in a row. So it was a penny for Hazard's thoughts when he was shown watching his team struggle and a goal down after 23 minutes.
However, Sarri did not rush on his key attacker and instead kept faith with what he had on the pitch, and was repaid with an excellent display thereafter.
Ruben Loftus-Cheek, brought back into the XI, led the fightback. After Pedro went close with a strike that drifted past Kevin Trapp's left-hand post, the England player kept the goalkeeper on his toes with a strike that also flirted with the woodwork.
The pair then combined for the goal. Eintracht's defenders lost possession after dawdling on the ball in the area, and Loftus-Cheek carved out an opening for Pedro to do the rest.
The Blues midfielder went close twice more, first with an effort that swept over the bar and then with a stinging shot with the outside of his boot that tested Trapp.
Brazilian Luiz went even closer with an blockbuster of a free-kick that dipped wickedly and crashed off Trapp's bar. Hazard, who came on in the 61st minute, then set up another opportunity for the defender, but this time he headed straight at the German keeper.
They should have won the game but will no doubt be content with how they began their ninth major European semi-final since the Roman Abramovich era began in 2003. A repeat display at Stamford Bridge should see them reach their sixth European final.
Eintracht tire after bright opening
Prior to kick-off, Eintracht supporters produced a spectacular display by holding up black and white cards in the team's colours, while at one end a giant tifo covered the entire stand.
Coach Ade Hutter's team lived up to the lavish introduction in the opening half hour, and underlined why they were unbeaten in 11 home games in the competition.
Key to their success so far has been the forward combination of Kostic and 21-year-old Serb Jovic, who is likely to be courted by several top European sides in the close season.
Jovic has been in outstanding form this season, during which he made his move from Benfica permanent, and gave Bundesliga's fourth-placed side the lead with a deft header from Kostic's delivery.
However, as Chelsea grew into the match, his team-mates appeared to lose their way. Eintracht's only clear-cut chance after the break fell to captain and defender David Abraham, who headed over from eight yards.
Pedro influential again - the stats
- Chelsea are unbeaten in their last 16 Europa League games, a record in the competition since it was rebranded in 2009-10.
- Eintracht Frankfurt have played 11 Europa League games at home, winning eight and drawing three. They haven't been behind for a single minute in those games.
- Just one of the six teams to draw the first leg of a Europa League semi-final away from home has been eliminated, Celta Vigo in 2016-17 (knocked out by Manchester United).
- Chelsea have scored the most goals (31) and had the most shots (217) in the Europa League this season.
- Pedro has been directly involved in seven goals in his last six starts for Chelsea in the Europa League (four goals, three assists).
- Jovic scored his ninth goal in this season's Europa League, only Olivier Giroud (10) has scored more.
- 24da Costa
- 5FernandesBooked at 61minsSubstituted forMendes Paciênciaat 73'minutes
- 20HasebeBooked at 58mins
- 11GacinovicSubstituted forWillemsat 90+2'minutes
- 6de Guzmán
- 39Mendes Paciência
- 27ChristensenBooked at 19mins
- 30David Luiz
- 12Loftus-CheekSubstituted forKovacicat 83'minutes
- 22WillianSubstituted forE Hazardat 61'minutes
- 10E Hazard
- Carlos del Cerro Grande
- Shots on Target
Second Half ends, Eintracht Frankfurt 1, Chelsea 1.
Offside, Chelsea. Kepa Arrizabalaga tries a through ball, but Olivier Giroud is caught offside.
Substitution, Eintracht Frankfurt. Jetro Willems replaces Mijat Gacinovic.
Foul by Olivier Giroud (Chelsea).
Martin Hinteregger (Eintracht Frankfurt) wins a free kick in the defensive half.
N'Golo Kanté (Chelsea) wins a free kick in the defensive half.
Foul by Mijat Gacinovic (Eintracht Frankfurt).
Foul by Pedro (Chelsea).
Luka Jovic (Eintracht Frankfurt) wins a free kick on the left wing.
Eden Hazard (Chelsea) wins a free kick on the left wing.
Foul by Sebastian Rode (Eintracht Frankfurt).
Mateo Kovacic (Chelsea) wins a free kick in the attacking half.
Foul by Sebastian Rode (Eintracht Frankfurt).
Mateo Kovacic (Chelsea) wins a free kick in the defensive half.
Foul by Danny da Costa (Eintracht Frankfurt).
Attempt blocked. Gonçalo Paciência (Eintracht Frankfurt) right footed shot from the right side of the box is blocked.
Attempt missed. David Abraham (Eintracht Frankfurt) header from the centre of the box is just a bit too high. Assisted by Sebastian Rode with a cross following a corner.
Corner, Eintracht Frankfurt. Conceded by Jorginho.
Hand ball by N'Golo Kanté (Chelsea).