Tatjana Maria upset defending champion Anastasija Sevastova in the Mallorca Open final to claim her first WTA singles title.

The unseeded Maria fought back from 4-0 down in the second set to pull off a surprise 6-4 7-5 win on Sunday.

Maria won 73 per cent of points on her first serve and broke four times in her maiden WTA final to take the title.

It was only a second win over a player ranked inside the top 20 for the German, who made only 11 unforced errors in a composed performance.

The 30-year-old world number 79 claimed the first break when the third seed was serving to stay in the match and pulled off an astonishing comeback in the second.

Sevastova came out swinging and looked sure to level at one set apiece, but the positive Maria came roaring back and celebrated a long-awaited triumph when her opponent drilled a backhand wide.