Adrian Ungur Adrian Ungur (born 22 January 1985) is a Romanian former tennis player who mainly competed on the ATP Challenger Tour. He was a member of the Romania Davis Cup Team and was coached by Fabrizio Fanucci. In June 2012, Ungur reached his career-h ...

was the defending champion when the event was last held in 2014 but chose not to defend his title as he had retired from professional tennis.

Holger Rune Holger Vitus Nødskov Rune (; born 29 April 2003) is a Danish professional tennis player. He has been ATP rankings, ranked as high as world No. 4 in men's singles by the Association of Tennis Professionals (ATP), making him the highest-ranked Da ...

won the title after defeating

Orlando Luz Orlando Moraes Luz (born 8 February 1998) is a Brazilian tennis player. He has a career-high doubles ranking of world No. 54 achieved on 9 June 2025 and a singles ranking of No. 272 achieved on 16 August 2021. Juniors Luz along with compatriot ...

1–6, 6–2, 6–3 in the final.

Seeds

Draw

Finals

Top half

Bottom half

References

External links

Main drawQualifying draw
{{DEFAULTSORT:2021 San Marino Open - 1 San Marino Open - 1

2021 Singles 1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to ...