Olympiakos risk losing their shared lead in the Greek Super League following a 1-1 draw with Iraklis.
Maresca put the defending champions in the lead after 40 minutes but Vellios silenced the home crowd with his equaliser in the dying seconds.
Panathaikos face Levadiakos in an away match on Sunday and a win would leave them in first place, two points ahead of Olympiakos.
Although PAOK Saloniki haven’t been able to keep up with Olympiakos and Panathinaikos, they are still ‘best of the rest’ following a 1-2 win at Panthrakikos.
Vieirinha opened the scoring in PAOK’s favor after 26 minutes, and Pablo Garcia added a second in minute 56.
Bedi Duval then pulled one back in the 69th minute, but PAOK held on to their 1-2 lead to defend their third place.
