The sixth seed triumphed 6-4, 6-1 over the Greek world number 101 on Court One.
However, the British number one shrugged off her title favourite tag.
"Everyone's a potential winner here. I'm here to hopefully be involved until the very end, but one match at a time," she said.
"I think it was quite tricky conditions out there today.
"It was a bit more gusty than maybe it appeared and it wasn't easy for both of us. I'm very happy to have tried to take care of the simple things, compete hard and make sure I left no stone unturned."
Konta next plays French 22nd seed Caroline Garcia on Monday for a place in the quarter-finals.
"The last time I played her I lost to her in a very close battle in Indian Wells," said Konta.
"She's obviously playing with a lot of confidence so I'm really looking forward to that, to play someone who's in good form who will really challenge me."
Wimbledon results on Friday, the fifth day of the 2017 championships at the All England Club (x denotes seeding):
Men
Third round
Benot Paire (FRA) bt Jerzy Janowicz (POL) 6-2, 7-6 (7/3), 6-3
Gilles Muller (LUX x16) bt Aljaz Bedene (GBR) 7-6 (7/4), 7-5, 6-4
Roberto Bautista (ESP x18) bt Kei Nishikori (JPN x9) 6-4, 7-6 (7/3), 3-6, 6-3
Marin Cilic (CRO x7) bt Steve Johnson (USA x26) 6-4, 7-6 (7/3), 6-4
Women
Third round
Ana Konjuh (CRO x27) bt Dominika Cibulkova (SVK x8) 7-6 (7/3), 3-6, 6-4
Elina Svitolina (UKR x4) bt Carina Witthoeft (GER) 6-1, 7-5
Johanna Konta (GBR x6) bt Maria Sakkari (GRE) 6-4, 6-1
Caroline Garcia (FRA x21) bt Madison Brengle (USA) 6-4, 6-3
Victoria Azarenka (BLR) bt Heather Watson (GBR) 3-6, 6-1, 6-4
Simona Halep (ROM x2) bt Peng Shuai (CHN) 6-4, 7-6 (9/7)