Speaking after the 25-21 win, O'Leary said: "We've got a great pack and traditionally we've always been strong, so this week we concentrated on keeping it basic and keeping it tight, you know, and the forwards delivered.
"It was an easy ride to be behind them to be honest. It's brilliant to get the win."
Success at the RDS, in the tightest of finishes, saw current champions Leinster remain third in the table, just two points off the pace.
Felipe Contepomi landed seven penalty goals in the 21-20 victory over Cardiff, taking his tally to over 100 points in the Magners League this season.
Reflecting on the province's fourth straight league success, man-of-the-match Rob Kearney said: "It was hairy stuff towards the end alright, but the high level of competition showed again tonight because everyone had to be on top of their game.
"Over the last three weeks we have been gradually building and tonight was a fantastic result. It was a very tough game and full credit to Felipe for kicking all his goals under pressure."
Munster's victory was one of three away wins in the round, while the competitiveness of the Magners League was once more borne out with all five round 10 games producing a bonus point for the losing team.
The challenge for the title is beginning to intensify as just five match points, or a bonus point win, now separate all the teams in the top half of the table.
2008/09 MAGNERS LEAGUE - AFTER ROUND 10:
TOP TRY SCORERS -
6 - Richard Fussell (Newport Gwent Dragons), Thom Evans (Glasgow Warriors)
5 - Luke Fitzgerald (Leinster), Doug Howlett (Munster)
4 - Keith Earls (Munster)
3 - Leigh Halfpenny (Cardiff Blues), Fionn Carr (Connacht), Darren Cave (Ulster), James Hook (Ospreys), Mark Jones (Scarlets), Deacon Manu (Scarlets), Ma'ama Molitika (Cardiff Blues), Timoci Nagusa (Ulster), Martin Roberts (Scarlets), Morgan Stoddart (Scarlets), Ceri Sweeney (Cardiff Blues), Nikki Walker (Ospreys)
TOP POINTS SCORERS -
114 - Felipe Contepomi (Leinster) (9 conversions and 32 penalty goals)
95 - James Hook (Ospreys) (3 tries, 13 conversions, 17 penalty goals and 1 drop goal)
93 - Dan Parks (Glasgow Warriors) (6 conversions, 24 penalty goals and 3 drop goals)
91 - Stephen Jones (Scarlets) (2 tries, 12 conversions and 19 penalty goals)
78 - Ian Keatley (Connacht) (1 try, 5 conversions, 20 penalty goals and 1 drop goal)
69 - Chris Paterson (Edinburgh) (1 try, 8 conversions and 16 penalty goals)
62 - Ian Humphreys (Ulster) (1 try, 12 conversions and 11 penalty goals)
53 - James Arlidge (Newport Gwent Dragons) (1 try, 6 conversions and 12 penalty goals), Ben Blair (Cardiff Blues) (1 try, 6 conversions and 12 penalty goals), Phil Godman (Edinburgh) (4 conversions, 13 penalty goals and 2 drop goals)
49 - Paul Warwick (Munster) (2 tries, 6 conversions and 9 penalty goals)
47 - Shaun Connor (Newport Gwent Dragons) (1 try, 6 conversions and 10 penalty goals)
44 - Ronan O'Gara (Munster) (10 conversions and 8 penalty goals)
31 - Ceri Sweeney (Cardiff Blues) (3 tries, 5 conversions and 2 penalty goals)
BEST PLACE-KICKERS -
85.71% - Chris Paterson (Edinburgh) (24 successful kicks out of 28 attempts)
85% - Phil Godman (Edinburgh) (17/20)
80% - Matthew Jarvis (Ospreys) (4/5)
77.36% - Felipe Contepomi (Leinster) (41/53)
76.19% - Shaun Connor (Newport Gwent Dragons) (16/21)
74.19% - Ian Humphreys (Ulster) (23/31)
73.81% - Stephen Jones (Scarlets) (31/42)
71.43% - James Hook (Ospreys) (30/42), Ian Keatley (Connacht) (25/35)
69.23% - James Arlidge (Newport Gwent Dragons (18/26), Ronan O'Gara (Munster) (18/26)
66.67% - Ben Blair (Cardiff Blues) (18/27)
63.64% - Rhys Priestland (Scarlets) (7/11)
58.33% - Ceri Sweeney (Cardiff Blues) (7/12)
57.14% - Dan Biggar (Ospreys) (8/14)
56.60% - Dan Parks (Glasgow Warriors (30/53)
55.56% - Leigh Halfpenny (Cardiff Blues) (5/9)
44.44% - Clinton Schifcofske (Ulster) (8/18), Colin Gregor (Glasgow Warriors (4/9)
33.33% - Niall O'Connor (Ulster) (2/6)
RESULTS ROUND-UP -
Friday, January 9, 2009 at the Sportsground
Connacht (6) 14: Ian Keatley(T/2P/D)
Scarlets (3) 17: Deacon Manu(T), Stephen Jones(T/2C), Rhys Priestland(P)
Connacht v Scarlets Match Report
John Muldoon Video Interview
Friday, January 9, 2009 at the Liberty Stadium
Ospreys (9) 21: James Hook(7P)
Munster (11) 25: Tomas O'Leary(T/P), Lifeimi Mafi(T), Paul Warwick(2P), Conan Doyle(2P)
Ospreys v Munster Match Report
Friday, January 9, 2009 at Firhill Arena
Glasgow Warriors (11) 20: Thom Evans(T), Dan Parks(4P/D)
Newport Gwent Dragons (15) 25: Rory Sidey(T), Richard Fussell(T), James Arlidge (T/2C/2P)
Friday, January 9, 2009 at Murrayfield
Edinburgh (18) 21: Hugo Southwell(T), Jim Hamilton(T), Phil Godman(C/3P)
Ulster (9) 15: Ian Humphreys(4P), Paddy Wallace(P)
Edinburgh v Ulster Match Report
Saturday, January 10, 2009 at the RDS
Leinster (9) 21: Felipe Contepomi(7P)
Cardiff Blues (11) 20: Andy Powell(T), Leigh Halfpenny(4P), Nicky Robinson(D)
Leinster v Cardiff Blues Match Report