The gap is closing but it's still there. For how much longer is possibly open to question but for the time being the maxim of the last three seasons remains true: when you're used to winning, you're used to winning.

This was Munster's sixth straight win over Ulster and their ninth win in a row this season.

Remarkably, for the fourth game running they didn't concede a try and by my calculations the last person to cross the try-line against them was Dan Luger, fully 385 minutes ago - not including injury time - and over two months ago. Of late it hasn't been pretty but it's been as effective as ever.

When it comes to grinding out or gutsing out victories it's doubtful whether there's ever been an Irish side quite like them. Ultimately, they hung on here by the skin of their teeth, and owe their place in the inaugural Celtic League final to the wit and defensive reactions of Jeremy Staunton as he cut out Tyrone Howe's attempted chip ahead for the try which would have set up David Humphreys for a match-winning 67th-minute conversion attempt.

It was justice of a sort in that Humphreys' pass to release Howe was clearly forward, and so Munster might have been wrongly denied a place in a final. On the balance of play, too, the better team won, but the close margin at the end was both a reflection of Munster's inability to press home their earlier advantage as well as Ulster's stickability and their David Humphreys-inspired ability to play catch-up.

Munster played better and more fluidly in their previous five wins over Ulster but both Declan Kidney and Mick Galwey pointed to this being cup rugby, and sure as Galwey pointed out, "we were reared on that."

"Sometimes these games are like that," said Kidney. "They were crowding midfield, dropping one of their forwards into midfield off line-outs, so there wasn't a whole lot of point in attacking with two players into that area where they already had three defenders. So that's why we had to try and make them turn today.

"In fairness, the players stuck to it, they agreed that that's what they should do. It's not what they like doing but that's what they had to do to win the game."

The chinks were few, the tackling and the physical toll immense. This was one of those games which you either went with or you didn't, and you probably had to be into it before it even started. Opinions as to its entertainment value varied afterwards. For an intrigued neutral or the partisan supporter it was absorbing from start to last, but for those of a more detached slant who wanted a try feast, forget it. This was never the one for them.

In many respects it went according to script, with both sides largely playing for territory and field position for the two best outhalves in the country to kick goals. Even without John Hayes, as expected the Munster pack bossed proceedings, exposing the mobile but non-heavyweight Ulster tight five. The Munster lineout maul went particularly well and so, too, their pick and go charges. Setting targets fairly close in, they were able to get numbers to rucks regularly, ensuring a steady stream of possession for Ronan O'Gara to establish overwhelming territorial supremacy.

This in turn was augmented by Munster's cuteness and patience in the aerial ping-pong, especially their outside three, although they were ably assisted: one piece of covering by Peter Stringer, whose work-rate was as usual outstanding, followed by a diving catch in the corner by O'Gara, helped to win one of the many duels in the sky.

Munster could have pulled away at various junctures had they converted try-scoring chances, such as the time Jason Holland failed to offload sooner to Anthony Horgan or Mike Mullins after an intercept, or when Jim Williams was held up over the line after a succession of drives off close-in lineouts. Credit to Ulster's resilience, though, and with O'Gara landing five from seven to Humphreys' three from three Ulster grew in belief the longer Munster failed to pull clear.

No-one orchestrates catch-up rugby better than Humphreys, who is then given full rein to display his gifts (remember the 14-point injury-time salvo for a draw away to Stade Franτais last season). And with the ever-dangerous running of Ryan Constable added to the mix, there was a very real chance they would pinch it. Why Alan Solomons doesn't trust the former Wallaby centre more is a mystery.

Granted he's been injured, but this was his sixth appearance as a replacement and though he's only started once this season, he still managed to score three tries, which is three more than Adam Larkin and the hard-working Johnny Bell combined.

Alan Solomons attributed this in part to the increased space as the match wore on, and reckoned that in another five minutes Ulster would have won, while Gary Longwell lamented Munster's ability to get ahead and thereafter keep the pressure on Ulster.

"We've felt we're getting better and better this season, and Munster have set the standards for the last three seasons. We're not there yet but December 28th gives us another chance, and we're getting closer."

The dust had scarcely settled, or in the case of Lansdowne Road the mud had hardly started to solidify again, when talk had already turned to an eagerly-awaited final between Leinster and Munster.

Deep down, all but the most parochial of Ulster supporters had thought it would come to this. Were he given a free £100 bet, Longwell admitted he'd "just about" put it on Leinster. "I honestly think Leinster are the best side in Ireland at the minute."

Potentially, it's the most intriguing and the most gripping domestic game in years.

Scoring sequence: 6 mins - O'Gara pen 3-0; 18 - O'Gara pen 6-0; 30 - O'Gara pen 9-0; 36 - Humphreys pen 9-3; (half-time 9-3); 44 - Humphreys pen 9-6; 46 - O'Gara pen 12-6; 55 - O'Gara pen 15-6; 83 - Humphreys pen 15-9.

MUNSTER: D Crotty; J Kelly, M Mullins, J Holland, A Horgan; R O'Gara; P Stringer; M Horan, F Sheahan, P Clohessy, M Galwey (capt), P O'Connell, A Quinlan, A Foley, J Williams. Replacements - J O'Neill for Kelly (4-14 mins), J Staunton for Crotty (72), M Cahill for Horan (77), M O'Driscoll for O'Connell (82).

ULSTER: P Wallace; S Coulter, A Larkin, J Bell, T Howe; D Humphreys, N Doak; J Fitzpatrick, P Shields, S Best, M Blair, G Longwell, T McWhirter, R Nelson, A Ward (capt). Replacements - P Johns for Blair (half-time), R Constable for Larkin (55 mins), M Crick for Nelson (60-63), N McMillen for McWhirter (63). Sinbinned - Shields (63-73).

Referee: I Ramage (Scotland).