Third Test - South Africa v British and Irish Lions
Venue: Ellis Park, Johannesburg Date: Saturday 4 July Start: 1400 BST
Coverage: Live on Sky Sports, BBC Radio Wales, 5 Live and live text commentary on the BBC Sport website
Williams' Lions record does not reflect his outstanding Wales career
Shane Williams says he is ready to shine against South Africa after being promoted to the Test side for his final game as a British and Irish Lion.
"It's my last chance so hopefully I can take it, why not go out in style?" said the 2008 IRB player of the year ahead of Saturday's third and final Test.
The Wales winger, 32, has struggled with form and fitness this season after a memorable, Grand Slam-winning 2007/8.
Ugo Monye and Luke Fitzgerald started ahead of him in the first two Tests.
"It's disappointing that the series has been decided [by two South African wins] before I've had the chance to start, but I was competing against great players," said Williams, Wales' leading try scorer with 46 from 65 caps.
"It was nice to have a couple of minutes [as a replacement] in the second Test, but I wanted to get on a lot earlier, I can assure you.
"We obviously can't win the series, but there are a lot of proud guys out there who are really looking forward to going out to prove that we did not deserve to lose the series."
While the standing of Amman Valley man Williams amongst the greats of the Welsh game is guaranteed, it has been suggested that the one thing missing from his record is an outstanding display for the Lions.
He toured with the 2005 Lions after Wales' Grand Slam success in that year, but only made the Test side against Argentina and for the second of the three-match New Zealand series.
On this tour he has seemed at times to be trying too hard, and his contribution to the first two Tests was limited to his replacement appearance for the last quarter at Loftus Versfeld.
For the final game of the tour at Ellis Park, Williams comes into a side showing eight changes.
Williams has endured a frustrating tour of South Africa to date
"The feeling is pretty good in the team, as it has been from the start of the tour," Williams told BBC Sport Wales.
"All the guys who have come in have trained well and performed in the midweek games.
"I think that a fair score in the series so far would have been one Test apiece."
Williams will face a Springboks side showing 10 changes, including an all-new back three.
Bulls full-back Zane Kirchner will make his debut in the number 15 jersey while Odwa Ndungane and Jongi Nokwe replace JP Pietersen and Bryan Habana on the wings.
"Like the players coming into our side, they will want to prove a point, there will be a lot of determined guys out there," said Williams.
"They will want a Test win over the Lions and will be pushing for starting places in the Tri Nations.
"Their back three - certainly the wingers - are fliers. I've been keeping an eye on them in the analysis. They score tries for fun."