Celtic slumped to a 4-1 defeat in Lisbon as Benfica stormed to a comfortable Europa League win, but manager Martin O'Neill insists the Hoops can still qualify for the knockouts

Determined Martin O'Neill maintains Celtic can still secure qualification for the Europa League knockout stages.

The Hoops suffered another heavy loss in Lisbon as Benfica cruised to a commanding 4-1 victory.

Celtic remain without points following two matches and now face a challenging task to progress to the next round.

Celta Vigo arrive at Parkhead for next Thursday's crucial encounter, but O'Neill remains optimistic about their European prospects.

He stated: "I genuinely believe that, as I said to you it's not bravado on my part here today, I would absolutely.", reports the Daily Record.

"I thought we showed in the second half that we were capable but in all honesty, despite the great chance we had to make it 2-1 a few minutes later, we were a bit passive.

"That might have just been early on in the occasion, it might have been the early goal that we conceded but I thought we did really well in the second half and it gives me a great heart and I feel that it says determinedly, we think we can do it.

"I know it's tough, six games to go but I think that we, our ambition is to try and make it."

Celtic conceded three goals before half-time as £64million striker Jhon Duran grabbed a double, while Alexander Bah contributed a third.

Camilo Duran pulled one back following the interval to offer the visitors brief encouragement before Vangelis Pavlidis sealed the result.

However, it proved another disappointing evening for struggling forward Kasper Hogh, who failed to find the net once more and was substituted at the break.

O'Neill acknowledged he faces a selection dilemma in attack ahead of Sunday's fixture against Hearts. He said: "I think it's a battle for places, it really should be, that's something I've just said to the boys in the dressing room.

"If you want to be part of this you've got to knuckle down, be a part of it, because we've got a long season ahead.

"We've got a big game on Sunday, another match in the Europa League coming up.

"Honestly there's a speedy determination within the group. It was tough the first half today but we got at them and we felt as if we could have done that a wee bit earlier."

Celtic endured yet another difficult evening on European soil as Benfica inflicted a third consecutive continental disappointment upon the Hoops.

With supporters directing criticism towards the boardroom, O'Neill was questioned about accountability for the club's persistent European struggles.

He said: "No, that's a big, big question. I haven't seen all the things that have happened over the last 20 odd years.

"I've just spoken to the Benfica manager before the game and naturally, although he wasn't here at the time, but they are massively disappointed that they're not in the Champions League.

"There's some really serious teams in this Europa League, but that aside, your question demands a longer answer than I can give at this minute."