Rufin achieved another landmark in his young career on 25 October 2009, when he won the Florianópolis Challenger title in Brazil, beating Pere Riba in the final, 6–4, 3–6, 6–3.

Rufin received a wildcard into the 2010 US Open and defeated Leonardo Mayer in four sets before losing to Paul-Henri Mathieu in the second round.

He defeated Canadian Vasek Pospisil 6–4 7–6 and Spaniard Feliciano López 7–6 6–3, before falling to compatriot Gilles Simon 6–7 7–6 2–6.

Rufin's four week sojourn on the clay courts of South America comprised a win in Villa Allende, two finals in Quito and Buenos Aires and a Semin-Final in San Juan.

Rufin reached the Quarter-Final of the ATP Tour event in Viña del Mar, defeating Spain's Rubén Ramírez Hidalgo 6–3 6–4 and Argentina's Juan Mónaco 7–6 6–4.