The Swedish musician is the highest placed out of all of the contenders, said the Official Charts Company.
His success lies in contrast to British entry Electro Velvet's entry Still In Love With You, which is in the low 50s of the top 100.
The UK's 1920s-influenced swing act finished 24th in the contest, out of 27 participants, with five points.
Zelmerlow's winning upbeat song, Heroes, was accompanied by innovative animated visuals and won 365 points in the contest.
Belgium's Loic Nottet, who came fourth at the weekend, sits at number 31 in the midweeks with his track Rhythm Inside.
On Tuesday, early sales figures indicated Russia's Polina Gagarina - who came second in the contest - was around the number 33 mark with her song A Million Voices.
Latvia's Aminata, who finished sixth, was at number 51 with Love Injected and Australia's debut in the contest, Guy Sebastian, at number 55 with his song Tonight Again.
Australia was invited to compete for the contest's 60th anniversary. It finished in fifth place.
Also low on the charts, Israel's Nadav Guedj was at number 60 with his song Golden Boy, and Estonia's Elina Born was at 71 with Goodbye To Yesterday.
The final chart positions will be revealed on Sunday.
Eurovision winner Mans Zelmerlow has soared to number five in the mid-week music chart with his song Heroes.