Northern Ireland manager Michael O'Neill admits the expansion of the European Championship has played a part in rejuvenating his in-form side.

The decision to increase the number of participants from 16 to 24 at the 2016 tournament has been divisive, with the continent’s heavy-hitters virtually guaranteed to qualify even if they experience the occasional bump in the road.

But with third place now good enough to guarantee at least a play-off, the prospects of less distinguished nations have been greatly improved.

If O'Neill's side can maintain their magnificent current form, they may not need the additional places, with yesterday's surprise 2-0 success in Greece extending their 100 per cent record to three matches and leaving them top of Group F by two points.

But O’Neill is in no doubt that the revised system has played a part in raising expectations around his squad.

“With third spot offering a play-off, the smaller nations have an opportunity now, which I believe is a good thing,” he said.

“It also helps the bigger nations, of course, because they should never miss out — a big nation should always qualify now for the Euros, which I think is what Uefa would like to happen.

“But I think it is also good that the smaller nations, the likes of ourselves, have the chance to go to a finals.

"It is very, very tough to get to a World Cup now... only 13 countries out of more than 50 from Europe can qualify, so it is much more realistic for us to get an opportunity through the European system. I'm a fan of it."

Northern Ireland’s dominant start to this qualifying campaign has led to renewed belief that the country can arrive at a major championship for the first time since the 1986 World Cup.

But, while fans may be forgiven for brushing up on their French skills, O’Neill is refusing to lose himself in the moment.

His pursuit of a place at the 2014 World Cup yielded just one victory, seven points and a fifth-placed finish — a return that means a spot in the top three remains the publicly stated goal.

“No, I’m not revising that aim at the minute. Our focus is still on third place,” he said. “What we have at the moment is fantastic, but, throughout a campaign, we have such a small number of players, it can be fragile.

"We can't look too far ahead. Whilst we have home games to look forward to, Greece, Romania, Hungary are all capable of coming to Belfast and beating us, so they will be tough, tough games.

“We just have to continue doing what we’re doing. We are doing very well away from home. This is a tight group which I’m convinced will go to the final set of fixtures and we intend to be in the mix for that.”

There were many Northern Ireland players with good reason to celebrate in Athens — starting with Kyle Lafferty, who scored and won man of the match for the third game in a row.

Jamie Ward also netted his second international goal and assisted Lafferty's second, while Gareth McAuley enjoyed a memorable 50th cap and Ben Reeves a high-profile debut off the bench.

But nobody will have been as satisfied as goalkeeper Roy Carroll, who was returning to his former home stadium having spent three seasons with Olympiacos prior to joining Notts County.

“It was a dream night,” he said. “First of all, it’s nice to come back to Greece and get a performance like that. I love this place — I lived here for three years and I had a really good time.

“We got the three points and everybody is delighted with that. Everybody can dream [of qualifying]. Hopefully we can push on. We’ve got another away game next month, against Romania.

“If we get a good result out there, you never know. Hopefully we can qualify, but it’s still too early to talk about that at the moment.”