Bosnian tennis player Mirza Basic dropped 69 places in the world rankings following his first-round exit from the ATP 250 series tournament in Sofia.
One year ago, Basic entered the 2018 Sofia Open as the world number 129, but seven victories in eight days - over Bulgarian wild-card Alexander Lazov, fellow countryman Tomislav Brkic, Florian Meyer of Germany, fourth-seed Philipp Kohlschreiber, another German Maximilian Marterer, former world No. 3 and three-time grand slam champion Stan Wawrinka, and Romania’s Marius Copil - saw him lift his maiden ATP Tour title and move up 52 spots to what has remained his career-high world No. 77.
Since then, Basic’s form has faltered and he is now ranked 168th in the world.
Damir Dzumhur has also slipped down the rankings to the world No. 56, as he is yet to win a competitive match in 2019.
There were no changes in the top 10, as Novak Djokovic, Rafael Nadal, Alexander Zverev, Juan Martin del Potro, Kevin Anderson, Roger Federer, Kei Nishikori, Dominic Thiem, John Isner and Marin Cilic all retained their positions.