Blessin, a top-level novice, arrived on the Italian riviera from Belgian team KV Oostende on Wednesday as Genoa try to climb out of the top flight’s relegation zone.
Genoa performed with more verve than under his predecessors Andriy Shevchenko and Davide Ballardini but missed some presentable opportunities.
They kept pushing for their first league win since mid-September after Andrea Cambiaso was sent off with 11 minutes remaining.
However they stay second-bottom in Serie A after their 20th match without victory, on 13 points, five behind Venezia who sit 17th and face champions Inter Milan at the San Siro later on Sunday.
Blessin was a left-field name for Genoa, as Oostende was Blessin’s first senior coaching position after coming up through the academy system at RB Leipzig.
He took over at Oostende in 2020 and led the team to fifth in the Belgian top flight. His former team sat 15th in the 18-team league, four points above the relegation play-off spot, when he departed for Genoa.