Swiatek, who has claimed four grand slam titles on the clay surface at Roland-Garros, continued her dominance on Tuesday as she emerged a 6-3 6-4 victor.
Wang started the match confidently, moving the world number one around the court early on, but Swiatek found her rhythm, earning a decisive break point in the sixth game before cruising to the first set.
The top seed managed to find a break in the opening game of the second set, but that lead proved difficult to maintain as Wang broke back instantly to take the next two games on the spin.
Swiatek, however, broke for a 3-2 lead and held her serve in the following game, but Wang continued to put on the pressure, winning her next two games to level the game.
The Pole would find yet another break of serve in the ninth game and was able to hold out to secure her passage to the quarter-finals in the French capital.
Swiatek will face Danielle Collins in the next round.
Data Debrief: Swiatek fights off inspired Wang
While the scoreline looked comfortable for Swiatek, it was far from it on Court Philippe-Chatrier.
In the opening set, Swiatek had 11 unforced errors compared to Wang's eight, while also hitting only nine winners.
But in a game filled with break points, Swiatek showcased her ruthless streak, converting four and saving six of the eight she faced.
The top ranked seed was pushed all the way by her American opponent, but came through a third-set decider to win 6-1 2-6 4-1 after Collins was forced to retire.
Swiatek asserted her dominance early on, racing into a 3-0 lead and remained in control for the rest of the first set, with Collins no match for the Pole.
However, Collins started with a three-game lead of her own in the second set, looking a completely different player to the one who first stepped out on Court Suzanne Lenglen.
The world number one did have two chances at 5-2 down to put the pressure back on her opponent, but Collins remained composed to take the game to a deciding third set.
But Swiatek would find her rhythm once again, racing into a four-game lead as Collins took a medical timeout off-court.
The American would emerge back on court to win her first game of the set but retired immediately after, handing the win to her opponent.
Swiatek will continue her quest for a fifth success at Roland-Garros on Thursday where she will face Zheng Qinwen, who beat Angelique Kerber.
Data Debrief: Swiatek marches on, just
Swiatek's love affair on the clay courts in the French capital continued, but it did not come without its nervy moments.
Despite dominating the opening set, Collins was impressive with her serve, scoring seven aces in the contest compared to Swiatek's two.
Swiatek's triumph saw her become the first Polish player in history to reach the Olympics semi-finals in the singles.
