Fenerbahce 1-0 Benfica
Egemen Korkmaz's header gave Fenerbahce a deserved Europa League semi-final first-leg win over Benfica.
Korkmaz pounced on a error by Benfica's Melgarejo to nod in at the far post.
Fenerbahce midfielder Cristian missed a penalty seconds before half-time after Gokhan Gonul was clipped by Ola John.
The Turks, in their first European semi-final, also hit the woodwork through Moussa Sow and Dirk Kuyt, while Nicolas Gaitan clipped the post in a rare Benfica opportunity.
Benfica, who were eliminated from the Champions League group phase by Barcelona and Celtic, had not lost since dropping into the Europa League but looked a shadow of the side that had breezed through the previous stages.
Instead, the home side, backed by a fervent support inside the Sukru Saracoglu Stadium, were well worth their victory in Istanbul.
Whether their slender advantage will be enough for them to become the first Turkish team to reach a European final since Galatasaray in the 2000 Uefa Cup remains to be seen.
Benfica have a formidable home record, having lost only to Barcelona at the Estadio da Luz this season, and will be confident of overturning their deficit in the return leg on 2 May.
But they will have to improve considerably on a performance where they only really threatened through Gaitan's second-half effort.
Few sightings of goal were forthcoming as the teams sized each other up in a competitive opening, before Fenerbahce's attacking play began to match the ferocity of their support.
Their first opportunity saw Gonul pounce on a loose pass in the Benfica midfield to slip in Pierre Webo, whose low right-wing cross was prodded wide by Sow.
Benfica were without influential skipper Luisao because of a thigh injury and they were missing the Brazilian centre-back's aerial prowess as an unmarked Sow headed Kuyt's right-wing cross against the crossbar.
The first half appeared to be petering out as it entered stoppage-time when Benfica forward John clumsily clipped the heels of Gonul inside his own penalty area.
Regular penalty-taker Cristian was given the task of punishing the Portuguese, but could only smash his low effort against the outside of Artur's right-hand post.
The Brazilian had to be consoled by his team-mates as he appeared to leave the pitch for the break in tears, but returned in a more composed state for the second half.
And the midfielder was instrumental as Fenerbahce pressed for the opener. His vicious 20-yard shot was helped wide by a scrambling Artur, before the goalkeeper had to be alert again as Raul Meireles thumped low towards his bottom corner.
Fenerbahce continued to press and moments later rattled the woodwork for a third time. Kuyt smartly turned inside the penalty area before arrowing a snapshot against the foot of Artur's left-hand post.
Finally, they were rewarded for their dominance when Korkmaz pounced after Melgarejo inexplicably headed another Cristian set-piece back into his own goalmouth.
Fenerbahce forward Dirk Kuyt:
"It was a great night for Turkish football. We may not have their quality but we have just as much fighting spirit as Bayern Munich and Borussia Dortmund."
Benfica coach Jorge Jesus:
"Normally we are a team that delivers when we find opportunities, but tonight we couldn't do that.
"But the result is not too bad, we will remain hopeful until the last minute of the second leg. We will be much better in Lisbon."