Last Updated: 13/03/14 10:08pm
Thanks for joining us on the live commentary. The second leg at the Estadio da Luz is next Thursday night, kicking off at 6pm GMT. Report and reaction to follow.
Sherwood is angered by Jorge Jesus' antics on the touchline. The Benfica boss seemed to raise three fingers at the Spurs dugout after that Luisao goal.
After Lloris saves a downward Garay header from a free-kick wide on the left, Luisao is first to pounce in the area and he smashes home his second goal of the evening from a tight angle.
YELLOW CARD! Vertonghen booked for a tackle that left Gaitan in pain. The Belgian will be suspended for the second leg.
Almost a howler from Lloris there! The ball bounces over his head at the edge of the area, and Rodrigo looks certain to run on and score - but the France goalkeeper manages to stick out a hand and put it out for a corner.
Spurs block a shot from Amorim at the top of the area, then Lennon sprints down the other end before being dispossessed by Fejsa in the box.
Eriksen's deep free-kick is nodded across goal by Kaboul but Oblak clutches the ball before it can reach Adebayor.
Eriksen brings Spurs back into the tie with an excellent free-kick from 20 yards out, curled over the wall and into the top corner, to the right of Oblak. Game on!
YELLOW CARD! Silvio is booked for bringing down Kane after a tidy bit of play from Spurs. The Benfica right-back will be suspended for the second leg.
Markovic is flagged offside as he tried to chase away from Vertonghen. Townsend is warming up, he could be on shortly.
From Amorim's corner, the ball is swung in and Kaboul is not marking Luisao closely enough. The Brazilian benefits by nodding the ball past Lloris for his side's second goal of this first leg.
Amorim dispossesses Kane in midfield and after a quick one-two, he's in on goal. His rising shot is tipped over by Lloris for a corner.
Adebayor wishes he'd left the ball from Paulinho heading towards Eriksen. His touch means the Dane is subsequently offside.
Lennon dribbles infield off the right flank across the top of the box and strikes a low shot on goal. Oblak gets down to save easily though.
Rodrigo chases Cardozo's flick-on and tries to loop the ball over Lloris, but he can't get it on target.
Luisao plays Adebayor onside from Eriksen's pass, but the big striker scuffs his shot poorly and the ball skews wide of goal. Probably the best opening Spurs have carved out.
Quick note on the betting - Spurs are now 11/2 to win on the night. Benfica are 1/2, and the draw is a 5/2 shot.
Chris Green from Huddersfield emails in to say: "That first half performance from Spurs was truly shocking!" But hopping_10 disagrees: "Spurs playing okay, just need to create more in the final third. I'm going Spurs 3-1 Benfica."
A tweet comes in from @im123: "Team selection again is going to cost us - how is Naughton our left back> He wouldn't get on an Irish League Team."
Half-time: Tottenham 0 Benfica 1 (Rodrigo 29). Spurs have been punished for Naughton's snoozing, but haven't created a great deal at the other end.
Paul Archibald emailed in earlier and he's back to say: "There, I said it before the game, Naughton isn't good enough for a League Cup tie, let alone a Europa League tie. Bad selection."
Eriksen spreads the ball left for Naughton, who runs into the area and crosses low - but Oblak saves at his near post.
Benfica coach Jorge Jesus performed a little dance after his side took the lead. Spurs, meanwhile, are struggling on the entertainment value front.
Amorim pops up on the left and Kaboul has to tackle and clear for, you guessed it, another throw-in.
Naughton is caught out in the left-back position, as the pass from Amorim down the right channel is perfect for Rodrigo. So is the former Botlon loan signing's finish, as he strikes a low left-footed shot with slight curl across Lloris and inside the far post.
Serbia winger Lazar Markovic, on whom Chelsea are understood to have first option should Benfica ever choose to sell, then bursts into the right side of the Spurs area but he loses the ball.
A lucky escape for Oblak, as Eriksen chased Kaboul's header towards the Benfica area. The goalkeeper had to retreat back into his own box before diving on the ball.
Spurs have now had four corners to Benfica's zero, but they're struggling to seriously test Oblak and his defence.
Kane heads Naughton's deep delivery down and Luisao puts the ball behind for a corner. The same Benfica player's clearance results in another corner, and then the visitors manage to get it away properly and regroup.
A right-foot shot from 20 yards from Sandro, who was picked out by Eriksen's pass from the right flank. It goes well over the bar, however.
Great footwork in midfield from Kaboul but the ball is then given away by Eriksen, who was trying to find Kane.
Oblak looked uncertain on that set-piece and Spurs may feel they can target the young Slovenia shot-stopper.
Spurs manage to win another free-kick, and this time Walker sends the ball high and deep onto the head of Kaboul, jumping next to goalkeeper Jan Oblak. The whistle blows for a foul, however.
YELLOW CARD! Sandro brings down Sulejmani in midfield after Eriksen's poor free-kick. A quick counter-attack ensued and the Brazil midfielder felt he had to foul the Serbian.
A cagey opening three minutes, then Adebayor tries to swing in a cross for Kane but it's headed away.
The referee tonight is Jonas Eriksson, from Sweden, who antagonised Manuel Pellegrini in Manchester City's recent 2-0 Champions League home defeat by Barcelona.
Price Boosts! A Markovic first goal is 10/1, while the same from Eriksen is 11/1 with Sky Bet. A 2-0 Spurs win is 11/1, while the same victory for Benfica is 16/1.
There were three 6pm kick-offs in the Europa League last 16 tonight. Here are those first-leg results: Basel 0 Red Bull Salzburg 0; Porto 1 Napoli 0; Ludogorets 0 Valencia 3.
Predictions are always welcome. Chris Green from Huddersfield emails in with his forecast: "Tottenham to win 1-0, with Adebayor scoring the goal." He also asks: "Do Tottenham have a realistic chance of winning the Europa League?" Many will fancy Juventus first, and probably then Napoli - but outside of the Italian duo, Spurs have a good shout.
Paul Archibald has emailed in to say: "Strange that Naughton is picked ahead of Rose. Kane up front to start!!! Soldado has not been playing well, but this is still a shock. Let's see who rises to the manager's challenge..."
Let's get to the betting. There's no clear favourite to progress through to the quarter-finals at this stage - Sky Bet price Spurs up at 10/11 to qualify, while Benfica are 4/5. As for the first leg itself, the home team are 11/8 to win, the visitors 21/10 and the draw is 12/5.
Here's the thoughts of assistant boss Steffen Freund, who's been speaking to Spurs TV ahead of kick-off: "We're playing 4-4-2. Harry Kane trained really well so he starts today, and we have Christian Eriksen back - he's fit and will bring some dangerous set-pieces. Benfica finished third in their Champions League group with 10 points - the same as Olympiakos - so we all know it's a massive game, and it's difficult to beat them. But I can remember the same time last season, we played here against Inter and we beat them 3-0. It's important we try to keep a clean sheet."
Overall, however, Tottenham have a very good record against Portuguese opposition in UEFA competition. They have won seven out of 10 encounters, with one draw and two defeats.
This is the first time Spurs have played host to Benfica since the two teams met in the European Cup semi-final in 1962. The first leg in Lisbon finished 3-1 to the home team, and Spurs could only win the return 2-1, so went out 4-3 on aggregate. Benfica beat Real Madrid 5-3 in the final in Amsterdam.
Get in touch with me throughout tonight's proceedings by emailing firstname.lastname@example.org or tweet me at @jonboy79.
Benfica, last season's Europa League runners-up, have been on a tremendous run of late. They come into this game having won 21 of their last 23 fixtures in all competitions, and lead the Primeira Liga table by seven points from Sporting Lisbon.
A slight surprise in Jorge Jesus' Benfica XI, with experienced Paraguay striker Cardozo shrugging off a back problem and getting the nod to start ahead of the Brazilian forward Lima. Defender Jardel has been suffering from a head injury sustained last month, but he is on the bench.
And the Benfica bench: Artur (GK); Jardel; Andre Almeida, Enzo Perez, Filip Djuricic, Nicolas Gaitan; Lima.
Here's the Benfica starting line-up: Jan Oblak; Silvio, Luisao, Ezequiel Garay, Guilherme Siqueira; Ruben Amorim, Ljubomir Fejsa, Miralem Sulejmani; Lazar Markovic, Oscar Cardozo, Rodrigo.
Sherwood has made three changes to the line-up that began that heavy defeat to Chelsea at Stamford Bridge last time out. Harry Kane makes only his second start of the season, while Christian Eriksen returns after two games out with a back injury. There is also a recall for Paulinho. Nabil Bentaleb drops to the bench, while Michael Dawson (hamstring) and Gylfi Sigurdsson miss out. Danny Rose was struggling with a knee injury but he is named among the substitutes.
Here's the confirmed Tottenham team for tonight's game: Lloris; Walker, Kaboul (c), Vertonghen, Naughton; Lennon, Paulinho, Sandro, Eriksen; Adebayor, Kane.
It's been a turbulent few days for Tim Sherwood and his Spurs players since their 4-0 Premier League humbling at Chelsea last weekend. Can they now gain an advantage over the Portuguese league leaders to take to Lisbon in a week's time?