It was Joensson’s first World Cup victory of the season as Russian Nikita Kriukov completed the podium.
Despite seeing Joensson pip him to victory in Finland, Peterson extended his lead in the overall sprint World Cup standings with nearest challenger Nikolay Morilov only managing eighth.
Peterson now sits on 542 points with Morilov on 428 and Russian Alexey Petukhov currently sitting third with 411 with just two rounds remaining.
In the women’s sprint, Marit Bjoergen raced to victory to extend her overall World Cup lead.
The Norwegian topped the podium after her third sprint win of the season ahead of Russian Julia Ivanova while Poland’s Justyna Kowalczyk took third.
Bjoergen sits top of the overall standings on 2095 points with Kowalczyk second on 2017.
American Kikkan Randall extended her lead in the sprint standings with a fifth-place finish and she now sits on 604 points - 138 ahead of nearest challenger Natalia Matveeva of Russia.