Full-back Rob Kearney, wing Luke Fitzgerald, hooker Matthew Rees, prop Adam Jones and lock Simon Shaw all gain call-ups for a game the Lions must win to retain any chance of taking the three-Test series.

Kearney replaces Lee Byrne, who has been struggling with a foot injury, while Kearney's fellow Ireland Grand Slam winner Fitzgerald takes over from Ugo Monye.

Monye blew two gilt-edged try chances during a 26-21 first Test defeat in Durban last Saturday.

And McGeechan has responded to South Africa's scrummaging demolition job five days ago by changing two thirds of the front-row.

Ospreys tighthead Jones now has the task of coping with Springboks scrum destroyer Tendai ‘The Beast’ Mtawarira, taking over from England World Cup-winner Phil Vickery, with Rees packing down instead of Lee Mears alongside Jones and Gethin Jenkins.

It is the first time the Lions have started an official Test match with an all-Wales front-row since 1955.

The fifth change sees Wasps and England lock Simon Shaw preferred to Alun-Wyn Jones.

Shaw, 35, first toured with the Lions in South Africa 12 years ago, although Saturday will be his Test debut.

McGeechan's second Test line-up comprises seven Irishmen, six Welshmen and just two from England - Shaw and flanker Tom Croft.

Alun-Wyn Jones drops down to the bench, but there are no places in the match-day 22 for Monye, Mears or Vickery.

Scotland's Ross Ford has been named as the back-up hooker, with England powerhouse Andrew Sheridan providing prop cover.

There is also a place among the substitutes for Wales wing and world player of the year Shane Williams, with Harry Ellis and Ronan O'Gara named as reserve half-backs.

McGeechan said: "As a squad, the Lions still have everything to play for.

"The players know that the outcome of the Test series comes down to Saturday, and they are determined to take the series to a decider in Johannesburg.

"There were many positives to come out of the first Test that we have built upon this week.

"We have made five changes to the starting XV, but it will not change the way we want to play.

"Both teams will be better for the run last weekend, and we know we will have to step up our performance to ensure that we again take the game to the opposition and are more accurate in taking our opportunities."

The selection of Kearney and Fitzgerald makes it an all-Ireland back three with Tommy Bowe, while Shaw finally makes the Test side after 16 matches and three tours in a Lions shirt.