Complex sentence: Koubek won his first ATP title in 1999 at Atlanta as a qualifier, he achieved this losing only one set in the whole tournament overcoming Sebastien Grosjean in the final 6-1 6-2.
Split into simpler sentences: Koubek won his first ATP title in 1999 at Atlanta as a qualifier. He achieved this losing only one set in the whole tournament overcoming Sebastien Grosjean in the final 6-1 6-2.