Julian Montoya's first-half hat-trick helped Argentina beat Tonga 28-12 for their first win of this year's Rugby World Cup on Saturday.
Montoya and the Pumas dominated the opening 25 minutes of the Pool C clash in Higashiosaka on their way to an important victory.
Tonga had no answers to Montoya, whose hat-trick helped inspire Argentina – coming off a narrow loss to France in their opener – to their win as they scored four tries.
The bonus-point victory boosted Mario Ledesma's Pumas, although Tonga were much improved after being dominated in the first half.
After a scrappy start, Argentina took the lead through Montoya, who dived over in the right corner following a nice move from a line-out.
The Pumas dominated territory during what was an otherwise stop-start opening 15 minutes before Montoya scored again thanks to the forward pack.
Tonga were rattled and found themselves 21-0 down after just 20 minutes, a bad turnover around halfway allowing Santiago Carreras to race away and score.
Montoya was unstoppable in the first half, forcing himself over from close range to to earn a hat-trick and Argentina a bonus point.
Tonga finally settled and found a response through Telusa Veainu before half-time.
A couple of huge hits highlighted an even start to the second half before Veainu dived over in the corner to close the deficit to 16 points with 15 minutes to play.
However, Argentina looked to slow the game down late on, ending their worst ever run of defeats at 10.
Marvellous Montoya lifts Pumas
The first half belonged to Montoya and it was what Argentina desperately needed. Tonga were unable to stop the hooker, who scored three tries and set up the Pumas' win. Montoya became the first hooker to score a hat-trick at a Rugby World Cup since 1999.
Argentina left with questions to answer
A bonus-point win was just what the Pumas needed, but they were unconvincing in the final hour. Argentina avoided a fourth straight Rugby World Cup defeat, although improvement defensively from Tonga saw them struggle after their fast start.
Argentina continue their campaign with a tough clash against England on October 5, while Tonga meet France a day later.