The 23-year-old world number five from Eslöv won 7–11, 11–6, 11–7, 11–7.
Möregårdh started the match shakily and lost the first set after losing five straight balls after leading 7–6.
In the second set, he rose against his good friend, who was training with the world number five in Malmö ahead of his comeback.
The 37-year-old Ovtcharov, ranked 32nd in the world, was a step behind and Möregårdh was able to win 11–6.
After that, the former German world number one had nothing to oppose.
Möregårdh showed that he is back after his injury break – an overexerted knee that caused him to miss the European Team Championships – and after the 3–0 victory over national teammate Anton Källberg and Friday night's win, another German now awaits in the quarterfinals – world number 12 Dang Qiu.
That match will be played on Saturday night.
