The Chelsea keeper made his bow at the age of 41 years and 66 days, with only Marco Ballotta - at 43 years and 252 days - older when making an appearance in the competitionMark Schwarzer has become the oldest debutant in Champions League history after starting for Chelsea on Wednesday.
The former Australia international was named in Jose Mourinho's team to face Steaua Bucharest at the age of 41 years and 66 days.
Only Marco Ballotta, who featured for Lazio against Real Madrid five years ago to the day when he was 43 years and 252 days old, has appeared in Europe's premier club competition at an older age.
Schwarzer joined Chelsea on a free transfer during the summer, having reached the Europa League final with previous club Fulham in 2010.
He also played in the final of the Uefa Cup for Middlesbrough in 2006, and retired from international football last month having earned a record 109 caps for Australia.
Speaking after the game, the Australian revealed his pride at featuring in tournament. He told reporters: “It was fantastic, who says dreams don’t come true particularly at the age of 41?
" I feel very honoured and privileged to have the opportunity to play in the Champions League and I feel very honoured that the manager trusted me to play tonight.
"I thanked him afterwards in particular and it was a great night, we finished with the result we wanted and we finished at the top of the group. "