Eddie O'Sullivan says Ireland beating the All Blacks is "not an accident any more" - but has cautioned the World Cup is still some way off.

"If we played New Zealand again next week, we'd probably beat them again," said ex-Ireland coach O'Sullivan.

"But I think, come the World Cup, things will even up again."

"There is a lot of water to flow under the bridge between now and next year," he added.

'Number one for a very good reason'

Ireland's latest victory over the All Blacks was their fifth win in eight contests against the three-time world champions.

Speaking on BBC Radio Ulster's Sportsound Extra Time, O'Sullivan, who coached the Irish between 2001 and 2008, added: "Everyone gets more focused for the World Cup, but I do think we're right up there.

"At the moment we are the better team. There's no debating that.

"So it's a very unusual place for New Zealand to be and a very unusual place for Ireland to be, but we're number one in the world today for a very good reason."

Despite his caution over how the World Cup may unfold, O'Sullivan believes Ireland's 2-1 series win will stand Andy Farrell's team "in good stead" for next year's campaign in France.

Prior to the last World Cup, impressive Ireland form saw the Joe Schmidt-led outfit become the world's top-ranked team a year before the tournament began in Japan.

Yet they disappointed once more on the biggest stage as they exited in the quarter-finals after a 46-14 hammering by the All Blacks.

Despite that, O'Sullivan scoffs at suggestions Ireland should be concerned about the possibility of peaking too soon for the tournament in France.

"I find that a difficult conversation because you've got to do what you've got to do," he added.

"You can't say, 'we don't want to win that Test series because we might peak too soon'.

"You've got to take what's in front of you. You've got to take the historical moments because they will stand us in good stead down the track.

"When we play New Zealand again, they are going to be more worried than we are.

"Ireland have emerged now as a team well capable of putting together really good gameplans and executing them under pressure - and the defence has improved as well."

Sexton's continuing importance 'a vulnerability' for Ireland

O'Sullivan also acknowledged veteran fly-half and captain Johnny Sexton's crucial importance to Ireland remains an area of vulnerability for Farrell's squad.

"If Johnny Sexton was to go down.....he's absolutely key to us. There's no saying otherwise," he said.

"Joey Carbery, for whatever reason, hasn't hit the straps and he was the guy we are looking to and the next man up, Jack Carty, who missed the tour through injury, wouldn't have huge experience.

"Also, if you look at the props situation, we were fine at the end of the day, but our two props [Andrew Porter and Tadhg Furlong] had to play 70 minutes of rugby.

"Very few international teams do that, so we are struggling a little bit in terms of depth in the front row.

"Injuries, loss of form, bad luck…..all those things can hamper you, but you can't think too much about that.

"You've just got to keep on building and building and putting fuel in the furnace for the next big test."