British and Irish Lions head coach Ian McGeechan labelled his side's last-gasp defeat to South Africa as one of the worst moments in his career.

McGeechan's side, needing a victory to have any chance of winning the series, led until the 74th minute but were downed 28-25 by a 53m penalty from replacement fly-half Morne Steyn with the last kick of the game.

The Lions had raced into an early lead with an inspired performance from full-back and try-scorer Rob Kearney but as the injuries mounted, the make-shift tourists began to wilt under Springbok pressure.

A Stephen Jones penalty, three minutes from time, brought the scores level at 25-25 but a moment of madness from Ireland's Ronan O'Gara handed Steyn the chance to break Lions hearts, and he duly delivered.

"It's certainly one of the biggest disappointments, because I think the players deserved more," said McGeechan.

"Just to see their faces afterwards was very sad. We haven't had the rub of the green on the field. The effort that has been put in by the players has been phenomenal.

"There's a lot of character in this group of players and we?ll be doing all we can to win the final Test."