Ireland were the dominant side throughout but while they did not build on a promising start, Ruddock was pleased with the way they kept plugging away and eventually saw off the Scots with a brace of late tries.
“We always felt there was a danger with this game but our defence was again superb and to not concede a score in international rugby is a fair achievement,” said Ruddock.
That defence will be tested next Friday night at Adams Park in High Wycombe by an English side who stuck 59 points on this Scottish side in Glasgow a few weeks ago.
The large crowd expected Scotland, who had lost all three games prior to this, to fade after Ireland blitzed them in the opening minutes with a superb individual try from Shane Layden.
The former Roscommon minor footballer, playing on his club ground, collected a Scottish clearance on halfway, dinked the ball over the initial tackler and then showed awesome pace to score.
Captain Paddy Jackson, who had missed with a 40-metre penalty after two minutes, was just off target with the conversion.
The Scottish scrum and lineout was in all sorts of trouble in the opening quarter, but while Ireland dominated in terms of possession, they did not hammer home their advantage.
Another break from Layden created the opening which led to Scotland conceding another penalty after 14 minutes, which Jackson kicked.
But Ireland were not able to add to that 8-0 lead and Scotland were let off the hook by some sloppy play from Ireland, despite some great work by JJ Hanrahan in the centre, while Foster Horan and Conor Finn always posed a threat out wide.
Layden needed to be alert to beat Scotland winger Michael Crawley to the ball as the visitors broke from deep after 25 minutes as they entered the home 22 for the first time.
Moments later out-half Harry Leonard, who has played half a dozen games for Edinburgh in the RaboDirect Pro12 this season, was off target with a penalty from the right, while Jackson also missed from 45m three minutes from the break.
Two more penalties from Jackson put daylight between the sides and allowed Ireland build the phases with a decent cushion under them.
The superb work of the Irish front row gave them dominance and the likes of Iain Henderson, Conor Gilsenan and Jack Conan thrived.
Inevitably, the pressure told and it was a sniping break off a scrum by the impressive scrum-half Luke McGrath, which sealed the deal after 63 minutes.
Jackson added the points to make it 21-0 and the margin of victory was all that remained to be decided after that.
Ireland were rewarded for a series of good surged when No 8 Conan managed to barge over seven minutes from time as the Scottish cover wilted.
It was a performance which probably deserved a much bigger winning margin but maybe Ireland are holding something in reserve for the huge task they will face against Junior World Championship runners-up England at the home of Premiership side Wasps.
But England face a tricky tie away to France in Vannes this evening and perhaps there might be just one side playing for a Grand Slam next Friday night.
Scorers for Ireland: Tries: Layden, McGrath, Conan. Con: Jackson. Pens: Jackson 3.
IRELAND: S Layden (Buccaneers/Connacht); C Finn (Buccaneers/Connacht), C Farrell (Dungannon/Ulster), JJ Hanrahan (UL Bohemians/Munster), F Horan (Lansdowne/Leinster); P Jackson (Dungannon/Ulster), L McGrath (UCD/Leinster); K McCall (Ballynahinch/Ulster), J Rael (Garryowen/Munster), P Reilly (Lansdowne/Leinster); I Henderson (QUB/Ulster), D Qualter (Buccaneers/Connacht); C Gilsenan (UCD/Leinster), A Conneely (Corinthians/Connacht), J Conan (Old Belvedere/Leinster).
Replacements: J Coghlan (UCD/Leinster) for Conneely 46; D Merrey (Clontarf/Leinster) for Reilly 58; T Beirne (Lansdowne/Leinster) for Qualter 63; C O’Connell (Galwegians/Connacht) for Rael; K Marmion (Corinthians/Connacht) for McGrath; C Marsh (Dublin University/Leinster) for Jackson, all 69; S Olding (Belfast Harleuins/Ulster) for Hanrahan 71; J Cawley (Leinster) for McCall both 71.
SCOTLAND: T Allan (Western Province); J Farndale (Edinburgh), M Bennett (Clermont Auvergne), F Russell (Falkirk), M Crawley Broughmuir); H Leonard (Edinburgh), M Torrance (Ospreys); R Hislop (Edinburgh), G Turner (Edinburgh), A Allan (Loughborough Students); A Redmayne (Dundee HSFP), J Gray (Hamilton); M Eadie (Bristol), W Bordill (Sale Sharks), J Swanson (Boroughmuir).
Replacements: A Sinclair (Stirling County) for Redmayne, 47; M McConnell (Glasgow Warriors) for Torrance, 52; R Anderson (Gala) for Bennett, 60; R Ferguson (Ayr) for Turner, 62; T Steven (Glasgow Hawks) for Crawley; C Reid (Edinburgh Accies) for Swanson both 68; G Robertson (Dundee HSFP) for A Allan 72; J Bhatti (Stirling County) for Hislop 71.
Referee: M Raynal (France).