Petkov has played for the Bulgarian national team as a backup to Zdravko Zdravkov and Dimitar Ivankov from 1998 until 2018, when he made his 18th and final appearance for his country at the age of 42.

Despite the bad results during the autumnal part of the season, after great matches in the spring, Levski Sofia fulfilled the plan before the term had set and became a champion for 26 time, before the last round has been played.

During 2009/2010 season, the Levski's team started their European campaign with 9:0 (on aggregate) in the second Qualifying round of Champions League against UE Sant Julià.

In 2009/2010 season, after couple of bad games and results, Levski however achieved qualifying for UEFA Europa League becoming 3rd in the final ranking.

Georgi Petkov signed for Enosis Paralimni on 21 January 2011, making a winning debut 24 hours later, by beating Ermis Aradippou 3–1 in Tasos Markou Stadium.

He played an important role in the penalty shoot-out held after the teams remained tied 0–0 after extra time, making two saves.

On 12 July 2018, Petkov captained Slavia in the 1:0 away win over Finnish team Ilves in the first qualifying round of the Europa League, becoming the oldest Bulgarian footballer to appear in a European club tournament match.

[6] In October 2018, after a 9-year absence from international duty and 20 years after his debut, he was recalled by Petar Hubchev for the UEFA Nations League matches against Cyprus and Norway.

[7] On 16 November 2018, in the 1:1 away draw with the Cypriots Petkov became the oldest European goalkeeper to play in an official match of their respective national team at the age of 42 years and 248 days.

The previous record holder was Elisha Scott who played for Northern Ireland at the age of 42 years and 200 days.