Wales captain Gareth Thomas says he was convinced he would be left on 99 caps after he was injured against Australia.
Thomas will reach the century landmark against Fiji on Saturday
"I was sure it had ended on 99, but it's a great achievement, I'll remember all 100 caps with pride," said Thomas.
Wales' record try scorer made a swift recovery from his rib problem and will become the first Welshman to 100 caps when he leads his side against Fiji.
The Cardiff Blues utility back, 33, is expected to retire from international rugby after the World Cup.
THE 100 CAP CLUB
George Gregan: 137
Jason Leonard: 118
Fabien Pelous: 115
Phillipe Sella: 111
Stephen Larkham: 102
David Campese: 101
Alessandro Troncon: 100
Thomas becomes the eighth player to reach the 100-cap mark in world rugby.
He follows George Gregan (137), Jason Leonard (118), Fabien Pelous (115), Phillipe Sella (111), Stephen Larkham (102), David Campese (101) and Alessandro Troncon (100).
The stakes will be high for Saturday's landmark game at Nantes' Stade La Beaujoire.
The winners of the match will advance to a quarter-final meeting with South Africa in Marseille's Velodrome on Sunday, 7 October (1400 BST), the losers having to go home.
I've only got this far because I've never sought it as a personal ambition
"The mind-set is positive and we go in believing that we can win," said Thomas, who plans to donate his jersey to Pencoed RFC where he started his career.
"People say that there is pressure from back home, but we'd be devastated as a team if we didn't reach the last eight, we see that as the lowest of our expectations.
"It's all about concentrating on our own game and being confident in what we bring to the table.
Born: 25.7.74, Ogwr, Wales
Position: Centre, wing, full-back
Clubs: Bridgend (twice), Cardiff, Celtic Warriors, Toulouse, Cardiff Blues
Wales debut: v Japan 27.05.95
Wales caps: 99 (39 tries)
Lions caps: 3 (1 try)
"If both teams get into their flow it could be a great match, Fiji will want that open game but we also feel that is how we play best.
"To get to the quarter-final on my 100th appearance would be fantastic for me - but more important to this young team.
"I've only got this far because I've never sought it as a personal ambition - it has always been about the team."
The Wales skipper, commonly known as 'Alfie', has had the most colourful of international careers.
He won his first cap against Japan in the 1995 World Cup, scoring a hat-trick of tries on his debut, the first three on the road to his record 39.
Since then he has played in all the three-quarter positions for his country and at full-back, proudly representing Wales in four World Cups.
Having had a reputation as something of a maverick in his early career and been out of favour in the Graham Henry era, Thomas emerged as a senior player and a squad talisman under Steve Hansen.
When Mike Ruddock took over as coach in 2004 he appointed Thomas as captain.
Thomas led Wales to the 2005 Grand Slam
Although injured in the Six Nations game against France, Thomas stayed with the squad as they marched triumphantly to the 2005 Grand Slam, and helped his club Toulouse win the Heineken Cup later in the year.
He made the summer Lions tour to New Zealand, starting all three Tests and taking over the captaincy when Brian O'Driscoll was injured.
But Thomas was embroiled in the turmoil of the "Ruddockgate" affair as Wales' Grand Slam coach departed in 2006.
Thomas made an infamous appearance on BBC Wales' Scrum V rugby show to defend the squad in the Ruddock affair, and later that night collapsed with a ruptured artery in his neck.
He battled back for club and country, regaining the Wales captaincy against England in this year's Six Nations and claiming the armband for the World Cup.