On Rugby: Of all the key moments in Leinster's season, none may prove more significant than the left-footed Biarritz scrumhalf Dimitri Yachvilli lining up a conversion no more than 10 metres to the right of the posts in the fourth minute of injury time at the Cardiff Arms Park on Saturday.

With Biarritz trailing the home side by 20-21, and having just mauled over the Cardiff line from a lineout for the third time, the normally reliable Frenchman pushed the winning kick wide.

Though one wonders what effect watching another of Munster's magnificent wins at Thomond Park had on their collective psyche, at a stroke Leinster were given every additional incentive by the events in Cardiff.

Sunday's gritty win in Sale thus pushed Leinster three points clear at the top of Pool Three and, such is the fluctuating nature of this season's Heineken European Cup that, conceivably, Leinster could copperfasten a place in the quarter-finals for the third year running this weekend.

Victory at home to Cardiff on Friday night at Lansdowne Road, with a bonus point, would leave Leinster on 19 points. Were Biarritz unable to win in Sale on Sunday, then they could not overtake Gary Ella's team when the sides meet in the south of France on Saturday week.

Similarly, were Sale still five points adrift of Leinster, they could not overtake Ella's team either on the final weekend, when they kick-off simultaneously away to Cardiff. In the event of Sale and Leinster finishing level on points, their final standings would be determined by the results of their head-to-head meetings, firstly the match points accrued, secondly the try count in the two games, and finally the better points difference from the two games.

On both match points and try count, the two sides accumulated the same tallies (five and three), and so Leinster would be ranked ahead of Sale by dint of outscoring them 45-39 in the two meetings.

All of this is conjecture of course, but at any rate not only is Leinster's destiny in their own hands but they are promisingly placed.

It's probably in Leinster's interests too that Biarritz are knocked out of contention by Sale this Sunday for two reasons. Not alone might it put Leinster into the quarter-finals, but Biarritz would be an altogether more dangerous outfit had they the chance of overtaking Leinster and winning the pool in that final head-to-head.

For Leinster to earn a home quarter-final they will probably have to win away on Saturday week as well as at home on Friday.

With a home quarter-final, which might also earn an additional € 500,000-plus, and with Felipe Contepomi and Brian O'Driscoll back on board, Leinster would be a serious threat then.

As with Munster, too, Leinster clearly benefited from having had an additional run-out as well as another week's full preparation after the disruptions over the festive period and the international camps. The IRFU director of rugby, Eddie Wigglesworth, ought surely to bear this in mind, for it is surely to Ireland's benefit in any Six Nations campaign if the bulk of the squad are on a high from reaching the knock-out stages of the European Cup.

There were countless other factors, not least that Leinster showed a bit of dog and were mentally right from the start. Perhaps it's no harm that Leinster were given a kick up the derriere by their defeat to Sale. No team has won the European Cup in the six years of its current format after winning all six pool matches, and it's been Leinster's misfortune that they've started like an express train only for their defeats to come at a more costly stage of the tournament.

Defensively, with Keith Gleeson outstanding, there was scarcely any comparison. Leinster kept their shape, concentration and width, coughing up only one dubious try from a turnover. Christian Warner's return brought a calming influence to Leinster's back play. He is elusive and deceptively quick, although Leinster still don't have a kicking game anything like Munster's or Ulster's.

The selection of Gordon D'Arcy was a masterstroke, not least in that it allowed them to exploit Brendan Burke's free running.

Aside from his outstanding defence, it was D'Arcy's (and Shane Horgan's) ability to break a tackle which created the two tries.

At any rate, it's advantage Munster and Leinster in their pools now, in what is shaping into the most competitive European Cup ever. Mathematically, with just two rounds remaining, 19 teams are still in contention, though as this includes Cardiff and Bourgoin, realistically that tally is more like 17.

As Edinburgh are the only unbeaten side in the competition (though they'll hardly survive their last-day trip to Toulouse), it's conceivable that for the first time five countries could be represented in the last eight.

Alas, the odds are against Ulster being in the shake-up. Sunday's turnaround at Leicester gives credence to Alan Solomons' claim they were punching above their weight. Although this Ulster outfit may have the resolve to overcome the scars of their Welford Road experience, they probably need to win away to Stade Francais now to have a chance of qualifying.

The other pity of the weekend was that London Irish didn't overcome Narbonne and give Connacht the glamour quarter-final pairing which their magnificent season deserves. Still, their previous two meetings with Narbonne over two legs suggests Michael Bradley's team have a 50-50 chance of reaching the Parker Pen Challenge Cup semi-finals, particularly as the coach's rotation policy is reaping dividends.

Finally, congratulations to Alain and Lizzy Rolland on the birth of their third child, Natasha.