Gauff needed just under an hour and a half to get the job done in Toronto, emerging a 6-4 6-4 victor to bounce back from her disappointment at the Paris Olympics.
The world number two started shakily, saving three break points in the third game before converting a break of her own to lead 3-1 in the opening exchanges.
Wang would fight back, however, winning the next three games on the bounce, but the American would rally to take the first set.
It looked as though Gauff would cruise to victory after taking a three-game lead, but her Chinese opponent would show her powers of recovery once more, levelling the encounter soon after.
The pair would trade blows for the remainder, with Gauff proving too strong for Yang late on, claiming the triumph with a love game on serve.
Gauff will face Diana Shnaider for a place in the quarter-finals following the Russian's triumph over Magdalena Frech earlier in the day.
Data Debrief: Gauff fights off spirited Wang
While Gauff was far from her best in Toronto, she adjusted well to the hard surface having competed on the clay courts of Roland-Garros at the Olympics.
The American impressed on serve, registering six aces throughout the contest while also winning 65% of her first-serve points.
Linette and Frech, ranked 48th and 57th respectively by the WTA, will both take part in the Olympic singles tournament at Roland-Garros, for which four-time French Open champion Swiatek is the firm favourite.
While Swiatek has been drawn to face Romania's Irina-Camelia Begu in the first round, Linette will face Mirra Andreeva and Frech is set to take on Bulgaria's Viktoriya Tomova.
Before then, though, the latter duo will go head-to-head in the final of the Prague Open.
Both overcame home favourites to advance to the showpiece match in Czechia, Linette beating first seed Linda Noskova 6-3 3-6 7-6 (7-2).
Frech, meanwhile, benefitted from a walkover against 16-year-old Laura Samsonova, the former Wimbledon girl's champion being forced to retire while down 3-6 6-0 4-2.
Frech, who is yet to win a WTA Tour-level title, won the only previous meeting between the pair in the Saint Malo quarter-finals in 2022, triumphing 7-5 6-7 (2-7) 6-2.
Linette, who beat Viktoriya Tomova and Linda Noskova on her way to the final, won in straight sets 6-2 6-1 as she now heads to Paris to face Mirra Andreeva.
The world number 41 was in the ascendency from the off, forcing a break in the fourth game and never looking back.
Despite the best efforts of Frech, who saved one set point, Linette continued to apply the pressure and another break put her a set up.
Linette would again break in the fourth game of the second set, winning three games on the bounce to secure her first career win over her compatriot.
Data Debrief: Linette prevails in first all-Polish affair
The final in Prague between Linette and Frech was the first all-Polish WTA level final in the Open Era.
Linette's triumph over her opponent was her first, having lost in the pair's previous encounter in Saint-Malo back in 2022.
During the contest, the world number 41 gave nothing away, saving all four of the break points she faced while converting three of the seven she had against Frech.
