Summer signing Isa Nacewa scored a try on his Magners League debut as Leinster began their title defence with a battling 16-16 draw with the Cardiff Blues, for whom Ben Blair tallied up 10 points.

This meeting of last season’s top two teams produced some very entertaining rugby in arguably the best conditions of a weather-hit weekend in Wales.

Both Cardiff and Leinster went through their pre-season schedules unbeaten and the visitors selected the same side that beat the Queensland Reds at the RDS last week.

That meant New Zealander Isa Nacewa kept his place at full-back, making his competitive debut behind a Brian O’Driscoll-Felipe Contepomi centre partnership.

Nicky Robinson became only the second player to reach 100 games for the Blues as he donned the number 10 jersey once again, while Richard Mustoe started on the wing for his first competitive appearance for the Welsh region.

Leinster were first off the mark as Contepomi converted a 10th minute penalty. However, the Blues also made a bright start with only handling errors preventing them from getting within scoring range.

Leinster’s second rows Malcolm O’Kelly and Devin Toner were energetic throughout, combining well with Bernard Jackman in the lineout and doing more than their fair share in broken play.

But the Scarlets back row of Maama Molitika, Martyn Williams and Andy Powell were the best unit on the pitch, hoovering up the ground, making the hard yards and putting in some bone-crunching tackles.

After Contepomi’s three-pointer, Cardiff enjoyed a rousing spell of possession in the visitors’ 22, where they set up camp for much of the opening half.

Had Rob Kearney not been in the right place at the right time to intercept a looping pass out to the right, the Blues would have been over for a certain try after engineering a two-man overlap.

The home supporters called for a deliberate knock on from Kearney and they did have a case, yet referee Andy Macpherson kept his yellow card in his pocket.

The game continued to simmer along as Ben Blair missed his first shot at the posts after a ruck offence from Jamie Heaslip, and then O’Driscoll showed his undoubted skills with a fine midfield burst.

Unfortunately for the Ireland captain, Leinster lost possession at the ensuing ruck and an interception by Martyn Williams allowed Robinson to launch a kick chase.

The Blues out-half must have thought he was dreaming when he saw the long-limbed O’Kelly outpace him and get back to retrieve the ball close to the Leinster posts.

Ireland’s most-capped player did just that before Michael Cheika’s men were able to relieve the pressure – but only for a couple of minutes.

The Blues grabbed their only try, 25 minutes in, when Blair scampered over in the right corner after taking a pass from Jason Spice.

The score was created when a Cardiff scrum, near the Leinster posts, wheeled to the right giving the home side a massive blindside to aim at.

A string of short passes later and Blair was touching down ahead of Kearney and O’Driscoll. The New Zealander got his breath back to slot the conversion and move his side 7-3 ahead.

30-19 winners at this venue last season, Leinster were struggling to find their usual rhythm and with props Gethin Jenkins and Taufa’ao Filise holding the upperhand, the visitors’ scrum was also under some pressure.

The Blues had the better platform up front and with the menacing Paul Tito swarming over the breakdown, their greater continuity enabled them to add to their points tally just before the break.

After another decent spell of possession play, Robinson pinged a drop goal through the posts from close range for 10-3.

Six minutes into the second half, David Young’s charges gained another kickable penalty for Blair but the full-back was off target and a well-struck Contepomi effort soon had Leinster within three points.

Despite the Blues continuing to look the more potent, their final passes were not sticking and Leinster’s rush defence was keeping them in the game.

With Jonathan Sexton called ashore and Nacewa switching positions, Leinster were beginning to look stronger on the counter as bodies began to tire.

A second drop goal from Robinson after his forwards had again laid the ground work pushed the Blues 13-6 ahead, only for Contepomi to tap over a simple 59th-minute penalty in reply.

Nacewa’s opportunistic try followed in the 63rd minute. The new recruit pumped a high ball into the night sky, the defending Mustoe lost his grip on the ball and O’Kelly, ever alert, was on hand to seize possession and put Nacewa cantering over for the score from 35 metres out.

Contepomi’s conversion was good and suddenly Leinster were 16-13 in front and contemplating a win that had looked beyond them at one stage.

Cardiff refused to wilt though and Blair booted them level with an excellent penalty strike from close to halfway, five minutes later.

The Blues threatened then through industrious number 8 Powell, who charged down a kick, and Nacewa was called on to clear the danger.

In a tense finale, Leinster got closest to nabbing the match-winning score as Kearney agonisingly pushed a drop goal attempt to the left and wide.

It would have been cruel on Cardiff had Leinster stole in for the win.

Young and his players will reflect on this as a missed opportunity and that will really hit home if they fail to overturn the Ospreys on Tuesday.

For Leinster, who ended their last campaign with back-to-back away defeats, these two points gained at the Arms Park could prove very valuable come the business end of the season.