Williams, who had been a professional for six years before Andreescu was born, took the first set and broke Andreescu at the start of the second.
On Saturday, she took charge of her match with Hsieh from the outset, producing the range of drop shots and changes of pace which have served her so well this week but playing with more obvious confidence.
Goerges beat the world No 50, Slovakian Viktoria Kuzmova, 6-1 7-6 (6) in first-up, before Andreescu beat Hsieh Su-Wei of Taiwan 6-3 6-3 to complete the day's play.
"What's really important for me is to stay in the present moment and I've been doing that all week and I'm beyond grateful right now".
Goerges is the defending champion and ousted Eugenie Bouchard of Westmount, Que., earlier in the week on her way back to the championship match.
"It's the biggest part I've learned in the last two or three years, when I got up the rankings", Goerges said.
And while one Canadian crashed out of the tournament in the quarter-finals, there was another who continued her giant-killing spree with a win over the sixth seeded Venus Williams.
Sharapova received off-court medical treatment between the two sets.
World No. 143 Andreescu saved 10 of the 12 break points she faced in a resolute display, managing to break through herself twice in each set on the Wozniacki serve to secure a 6-4, 6-4 victory.
But with the next point she ripped a victor and on her third matchpoint Kuzmova cracked a return straight into the net.
Andreescu has now played seven matches to just four for Goerges to reach the final.
"I tried to do that in the second as well, but I was too passive for my ways". I had an awesome week, I beat a lot of top players.
A qualifier for this tournament, Andreescu said her goal was "maybe to qualify" and "get a couple of rounds in".
"This meant a lot", Goerges said.
"Canada has gone from being a minor nation in tennis", says Roth, "Sure, we've always had a few players who were good, to now being a legitimate force in the tennis world".