Top-ranked Ireland gambled on fielding its first team against Tonga at the Rugby World Cup on Saturday just a week out from a huge showdown with defending champion South Africa.

The Irish green machine — playing in white shirts for a change — made it pay off, putting eight tries past the Tongans in a clinical 59-16 mauling that has confidence sky-high ahead of the game of the pool stage on paper against the No. 2 Springboks next Saturday.

As a bonus, Ireland captain Jonathan Sexton picked up a try between the posts in his 16 points and went past compatriot Ronan O’Gara and Wales' Neil Jenkins into fourth on rugby's all-time international points list. The 38-year-old Sexton is now Ireland's record-holder.

Powerhouse center Bundee Aki burst through the Tongans for two tries on the night in Nantes, where everything fell into place perfectly for Ireland.

Crucially, there were no major injuries and Ireland looked as ready as it could be to meet the Springboks by extending its national record winning streak to 15 tests with its second-best World Cup victory. It came one week after the best, an 82-8 thumping of Romania to open a campaign that's looking increasingly like Ireland's best ever chance of winning rugby's big one for the first time.

“It’s on to the next week now, it’s a massive game for us against the reigning world champions," Sexton said. "It’s all geared towards that now.”

South Africa has a chance to reply when it plays minnow Romania on Sunday, although no matter what the Boks do in Bordeaux, they can't catch Ireland at the top of Pool B for now.

WALES 28, PORTUGAL 8

Wales got a bonus-point fourth try in the last play to beat Portugal without ever completely subduing the feisty underdog appearing in its first Rugby World Cup game in 16 years.

No. 8 Taulupe Faletau rumbled through three tired Portugal tackles for the final try, ensuring Wales still came away to set the pace in Pool C with maximum points after starting with a gruelling 32-26 win over Fiji.

Louis Rees Zammit opened the try count for the Welsh in the ninth minute and celebrated with a version of Cristiano Ronaldo’s famous siuuu! leaping celebration — a cheeky take on Portugal’s most famous sports star.

Hooker and captain for the day Dewi Lake drove over from a tap penalty. Regular skipper Jac Morgan, who was called into the team at the last minute to replace Tommy Reffell, got Wales’ third.

But Wales still didn’t run away with it and the biggest cheer of the day in Nice came when Portugal pulled off a slick lineout trick that resulted in flanker Nicolas Martins scoring down the short side after an airborne Rafael Simoes flicked him the ball.

Portugal finished with 14 men when right wing Vincent Pinto was given a yellow card when he jumped for a catch and stuck a foot out into Josh Adams' face. It was upgraded to a red card for the third sending off of the World Cup so far following England's Tom Curry and New Zealand's Ethan de Groot.

Wales has Australia next in what might be a telling matchup for the pool. The Aussies face Fiji on Sunday. Portugal will have renewed hope of getting a first Rugby World Cup win against Georgia.

SAMOA 43, CHILE 10

Like Tonga and Portugal, Samoa opened its campaign nine days into the World Cup. The Samoans started slowly but ultimately overwhelmed tournament debutant Chile 43-10 in a game drawn out by penalties and punishments, including four sent to the sin-bin, two from each team.

After conceding an early try and leading only 19-10 at halftime, Samoa pulled away. Samoa’s five tries in all went to fullback Duncan Paia’aua right on the first-half buzzer, and blond-mulleted scrumhalf Jonathan Taumateine, flanker Fritz Lee and hooker Sama Malolo in the second half, with Malolo scoring twice.

Samoa coach Seilala Mapusua got a reaction from his men and 24 unanswered points after giving them an unrepeatable halftime dressing down.

“Probably a few words I can’t say on live TV,” he said when asked what his team talk entailed.

Samoa's ambitions of making the quarterfinals for the first time since 1995 will rest heavily on a meeting next with Argentina. Chile goes up against England.