(Reuters) - Samoa took advantage of Tonga having two players sent to the sinbin within minutes of each other in the second half to record a 25-17 win in a mud bath at Apia Park in the Pacific Nations Cup opener on Saturday.
Torrential rain before kickoff had also left ankle-deep puddles on the ground.
Tonga were forced into late changes for the game with number eight Nasi Manu, who was named on Thursday to lead the side, ruled out for the tournament with an unspecified injury.
Samoa dominated much of the match, especially in the forwards, where number eight Afa Amosa was outstanding with the ball in hand and was the beneficiary of a pushover try in the final 10 minutes.
Centre Alapati Leiua also scored early in the second half following a line break from Amosa as the home side dragged themselves back into the game from a 10-3 halftime deficit.
Inside centre Cooper Vuna and prop Ben Tameifuna had scored first half tries for Tonga, despite the visitors spending much of the first spell under pressure inside their own territory.
Leiua’s try in the 44th minute levelled the scores at 10-10 before flyhalf Ulupeno Seuteni gave the Samoa their first lead of the game.
Replacement hooker Sefo Sakalia’s converted try following a sustained buildup that went through 15 phases gave Tonga a 17-13 lead.
Poor discipline inside their own 22-metre area, however, led referee Mike Fraser to send Fotu Lokotui and Sakalia to the sinbin, with Amosa crashing over while both were off the ground.
Samoa winger Belgium Tuatagaloa ended the scoring in the final minute.
The tournament is a crucial buildup for the Pacific nations ahead of the World Cup in Japan in two months time, with Japan, Canada and the United States also taking part this year.
Japan host Fiji in Kamaishi later on Saturday while the United States play Canada in Denver.
Writing by Greg Stutchbury in Wellington; Editing by Amlan Chakraborty