Montoya the hat-trick hero as Argentina beat Tonga at Rugby World Cup

Montoya's treble at the Hanazono Stadium equalled Argentina's record for the most tries in a single World Cup match set by centre Martin Gaitan, now a member of their coaching staff, in a 67-14 rout of Namibia at Gosford, Australia in 2003.

It also meant that, with six in total at the global showpiece, Montoya has scored more World Cup tries than any other hooker.

Argentina had a four-try bonus-point as early as the 26th minute and the Pumas led 28-7 at half-time.

In a 'group of death' also featuring in-form England -- their next opponents in Tokyo on October 5 -- Argentina badly needed a bonus-point victory from this match to maintain their hopes of reaching the knockout phase following an agonising opening 23-21 loss to France.

"I thought we were very good in the first half and not in the second half," said coach Mario Ledesma.

"We have a very big week to prepare a final against the English next week so there is a lot of work to do," added the coach.

Tonga too were looking to bounce back after a 35-3 defeat by England. 

But it was 2007 and 2015 semi-finalists Argentina who opened the scoring with a seventh-minute try straight off the training ground.

They declined an easy penalty and kicked for a line-out close to Tonga's line.

After Montoya threw the ball in, Argentina won possession and lock Guido Petti quickly passed the ball back to the hooker on the blindside for a well-worked score.

Fly-half Benjamin Urdapilleta, preferred to Nicolas Sanchez, then made light of a difficult conversion from 45 metres out on the right.

Argentina's second try in the 17th minute was a similar story, although this time Montoya went over from a conventional line-out catch and drive. 

- Sustained forward pressure -

Minutes later, Argentina had their third try when Tonga fly-half James Faiva's careless flicked pass went to ground and Pumas left wing Santiago Carreras seized on the loose ball to sprint in from 55 metres out.

Urdapilleta, a key figure at French champions Castres, again converted to make it 21-0, much to the delight of Pumas' fans in a crowd of more than 21,000. 

Argentina then had their bonus point and Montoya his hat-trick when the hooker, who also scored a try against France, powered over from the base of a ruck.

But an Argentina fumble following Urdapilleta's fourth successful conversion at the restart led to a Tonga try in the 30th minute.

A spell of sustained forward possession ended with scrum-half Sonatane Takulua's wide pass to fullback Telusa Veainu, who sprinted in between two defenders.

Takulua converted and Tonga nearly scored another try in first-half stoppage time only for wing David Halaifonua to be bundled into touch by Tomas Lavanini's last-ditch tackle just before he grounded the ball.

It looked as if Lavanini had made an illegal shoulder charge but South African referee Jaco Peyper, after consulting the television match official, decided the lock had made a fair tackle. 

Montoya's hopes of equalling the record of most tries by a hooker in a World Cup match -- Ireland great Keith Wood scored four against the United States in 1999 -- ended when he was replaced five minutes into the second half.

Amid a welter of changes made by Pumas coach Mario Ledesma, doubtless with an eye on protecting key personnel for the England game, Argentina's performance level dipped.

Tonga, however, rallied, with replacement wing Cooper Vuna's pass sending Veainu in at the corner for his second try 14 minutes from time. 

But Faiva missed the conversion, with Tonga winless at this World Cup ahead of their October 6 match against France, a team they famously beat at the 2011 edition.

"We didn't get off to a good start. We gave away a couple of easy tries so that hurt us in the end," grumbled coach Toutai Kefu.