Scotland centre Sean Lamont marked the 100th cap for his country by firing a warning to their World Cup rivals to underestimate them at their peril.

Lamont reached his milestone as a second-half substitute in the kamikaze 36-33 win over Samoa at St James' Park which earned the Scots a quarter-final clash with Australia at Twickenham next week.

And despite the nerve-shredding finale to his side's Group B campaign, Lamont believes Scotland have never been better equipped to seize the initiative and march even further into the tournament.

Lamont told Press Association Sport: "This is by far the best Scotland team I've been involved in in my 11 years of playing - not just in the talent but the way the boys fight for each other.

"We've got a lot of belief and the general team spirit is brilliant. We can go a long way if we continue to show that level of belief and confidence.

"We are ready for next week and of course we will be the underdogs, but Scotland relish being the underdogs. You can take us for granted all you want, and you'll get a bite on the arse."

Scotland's struggle to assert themselves in the early stages of their Group B pool matches threatened to cost them dear as they trailed the already-eliminated Samoans 26-23 after a high-octane first half.

But the canny boot of Greig Laidlaw once again saved the day with the scrum-half scoring 26 of Scotland's points, including, fittingly, the last of three tries which finally put the game beyond their plucky opponents.

Meanwhile Lamont, who coincidentally also won his first Scotland cap against Samoa in 2004, said his personal achievement paled into insignificance compared to his country's march into the last eight.

Lamont added: "It's a great feeling to win 100 caps but I didn't really care if I got on the field - it was all about Scotland winning and that was my main focus today.

"I'm really happy to have got it and it's a big milestone for me, but during my time in the team I have realised it is about the team first and the individual second, and that's the kind of squad we are."

Scotland coach Vern Cotter had made seven changes from the side beaten by South Africa last week, including the reintroduction of the likes of fly-half Finn Russell, who missed out with an ankle knock.

So it will have come as a source of some frustration for Cotter that, just as in each of their previous three Group B fixtures, a sluggish start threatened to undermine an otherwise resolute team performance.

And it is something Russell himself concedes his side still need to address as they begin their build-up to the showdown against the Wallabies next week.

Russell said: "It's disappointing not to have the first half we wanted again, but we have to give credit to Samoa who were outstanding, and we knew what we had to go out and do in the second half.

"We can take some positives out of the game - we were outstanding at the set-pieces - but we also know there are some things we need to improve. We know what we have to do and from now it is knockout rugby and that's all that matters."