:::::Every player registers an English name with the ITF, otherwise they cannot play internationally. His player name "Lukacs Denes" is used in all results, draws, on the scoreboard, and on the official tennis sites (ITF, ATP, WTA). Journalists who write about tennis, take the names from these official sites. That's why we always find the non-diacritics names in the vast majority of reliable sources about tennis. So, that the title we should use for the article.