Poland's Swiatek, a six-time Grand Slam champion, reached just her second WTA semi-final this year after Rome and seeks her first final since winning the Korea Open almost a year ago in Seoul.
will face either Ukraine's Elina Svitolina or Russia's seed Ekaterina Alexandrova on Wednesday for a place in the final.
"From the beginning I went for it. I felt like I could dominate," Swiatek said. "I was quite happy with the way I played."
The 25-year-old world number eight from Warsaw will on Wednesday face Ukraine's ninth-ranked Elina Svitolina, who rallied past 19th-ranked Ekaterina Alexandrova 3-6, 6-0, 6-3.
"It was a tricky match with the wind," said Swiatek. "It was the first chance I had to play in the wind since I got here. I thought I needed to adjust to that. I just wanted to be more solid."
Swiatek dropped only three points on her first serve and took 11 of 16 points returning Shnaider's second serves.
Shnaider, a left-hander, swatted a backhand over the baseline to surrender a break in the opening game. But Swiatek took a 5-2 lead, breaking again when Shnaider netted a backhand, and served out to take the first set in 31 minutes.
Swiatek broke for a 2-1 lead in the second when Shnaider netted a forehand. She smashed a forehand winner to break a second time for a 4-1 advantage and again in the final game when Shnaider sent a forehand long.
Svitolina rallies
Svitolina won eight consecutive games in the second and third sets to dispatch her Russian rival in 93 minutes.
Svitolina sent a backhand long to drop serve to love in the final game of the first set, Alexandrova taking it after 29 minutes with 12 winners to only three by Svitolina.
In the second set, Alexandrova sent a forehand long and netted two backhands to hand Svitolina three breaks.
Svitolina served for the match in the eighth game of the final set but double-faulted away a break, only to break back to love in the last game, smashing a service return winner to end it.
Now, she moves to the semis to face Swiatek, who leads 4-3 in their WTA career rivalry but lost both their meetings this year.
"Very pleased with my performance. With the fighting spirit," said Svitolina. "She was playing really well in the first set. I had to really step into like a fighting mode."