Replacements used: Stuart Morrow (Ballynahinch) for Ryan (50 mins), Alan Kingsley (Young Munster) for Keeshan (60), Damian Hall (St. Mary's College) for Donnellan (67), Ciaran Kavanagh (Clontarf) for Condon, Liam Og Murphy (Young Munster) for O'Mahony (both 70), Not used: Ger Slattery (Young Munster), Matt D'Arcy (St. Mary's College).
Replacements used: Tom Standfield (London Scottish) for Hall, James Ngan (Barking) for Wheatcroft, James Stephenson (Blackheath) for Vincent (all 54 mins), Stefan Liebenberg (Blackheath) for Spencer, Dan Lloyd-Jones (Barking) for Pape (both 67). Not used: Alex MacKenzie (Barking), Mike Waywell (Fylde).
The game was six minutes' old when England Counties scrum half Ben Spencer split the posts after the hosts' experienced out-half Barry Keeshan had infringed.
England Counties could have stretched their lead four minutes later, but centre Peter Hodgkinson knocked on as the visitors spread the ball wide outside the Irish 22.
In the 18th minute, Ireland were given their first chance to respond. However, Keeshan's penalty from the halfway line drifted just left of the uprights and wide.
A Spencer kick from inside his own half went dead, and following a good drive from Irish pack, Keeshan got the opportunity to put Ireland on the scoreboard with a penalty from 30 metres, but it rebounded off the right hand post.
After a Hodgkinson break brought England up towards the Irish try-line, an English try looked imminent but tremendous Irish defending forced a knock on as the visitors drove towards the corner on the half hour.
At the other end, it looked like the Ireland Club team's captain Frank Cogan had broken through the English defence minutes later, but the pass that found him was ruled forward.
Back came Ireland and although the home back-line never really got going in the first half, they showed glimpses of their explosive pace and attacking quality.
When full-back John O'Brien gathered an up-and-under on the English 10-metre line, the Irish backs pounced. Phase after phase brought them closer to the English whitewash, but the move seemed dead when Keeshan slipped.
Referee Leighton Hodges then called play back for an earlier English infringement and Keeshan made no mistake with his third kick to put Ireland on the scoreboard at 3-3.
England Counties had the opportunity to score just before the half ended but again, they lacked the killer touch. Team captain Gareth Collins skipped past the Irish defence before offloading to David Vincent, but the winger was put into touch.
The second half took off where the first ended, with England Counties inside the Irish 22, but David O'Mahony's men seemed to be in the ascendancy.
After Steve Pape made a break, a Dan Mugford cross-field kick was taken in flight by John Cleary and the Galwegians clubman quickly turned defence into attack.
Cleary stormed clear of the English cover, only to be called back for an English penalty. Having decided to go for the corner, the Ulster Bank League aces then turned the ball over.
When a sustained period of English pressure again brought the visitors to within metres of the Irish line, it seemed England Counties would finally break the resolute Irish defence but again O'Mahony's well-drilled side turned the ball over.
After Cogan brought Ireland up to halfway, on the right touchline, they quickly spread the ball wide and crucially scored the game's first try.
When Old Belvedere's own David Mongan received the ball 10 yards in from the left touchline, it appeared that Vincent had time to close the him down, but Mongan, one of the best finishers in the club game, showed a blistering turn of pace to leave his opposite number for dead and touch down to the left of the posts.
Keeshan dragged his conversion attempt wide, leaving the scoreline at 8-3 to the men in green. Spencer missed the opportunity to bring England Counties to within two points when his 54th minute penalty sailed to the right and wide.
The English outfit's missed opportunities gave the impetus to Ireland and when they turned the ball over five metres from the English line after a period of renewed pressure, lock Simon Crawford drove over for his third try in the space of a week - he dotted down twice against the Scots.
The try was unconverted and now 13-3 down, England Counties responded almost immediately.
The broke their try-scoring duck in the 60th minute with Hodgkinson charging into the Irish 22 before offloading to skipper Collins who raced clear to touch down in the corner. Spencer was off target with the extras, leaving it 13-8.
Despite a late flurry from England Counties, the Irish defence held firm with wave after wave of attacks held at bay.
It was left to replacement out-half Alan Kingsley to seal the Ireland Club side's first ever unbeaten campaign.
He knocked over a final penalty as the game went into added time, sealing a gritty win which was built on a hugely committed and well-marshalled defence. They also showed more cutting edge in attack than their opponents.
Referee: Leighton Hodges (Wales)