Pavlyuchenkova was the first to advance, coming within points of winning the first set but losing it, but then grinding for almost two and a half hours to beat No.4 seed Angelique Kerber, 57 63 76(3).
"I just tried to stay calm and keep playing my game," Pavlyuchenkova said. "After I lost the first set I was a bit more relaxed even, so it was easier to focus on my game and my technique, and on every point. I think I had too much emotion in the first set, but from the second set I felt much better.
"Making the semis here in Paris is special. It's such a nice tournament and I love being here."
"The quarterfinals of the French Open in 2011 was something very special for me, as well as doing it at the US Open that year too," she said. "I was only 19 and the Grand Slams are especially big for us.
"I'm working hard and I look forward to hopefully having more of those results in the future."
The former World No.13's win over World No.9 Kerber was the 14th Top 10 win of her career.
Sharapova beat Pavlyuchenkova in their only previous meeting, but it was a three set thriller in the semifinals of Cincinnati in 2010, with Sharapova originally leading by a set and a break, dropping the second set, then reeling off four games in a row from 2-all in the third set to close it out.
"We haven't played against each other in quite a bit of time," Sharapova said. "She's playing really well this year and had a great win today, so I'm sure she'll be really confident going into tomorrow.
"It's always tough to play another Russian but it's good to know one of us will be in the finals."
The other two quarterfinals saw Alizé Cornet beat Andrea Petkovic in a three-hour, two-minute thriller, 76(6) 57 63, missing out on three match points in the second set and having to rally from 3-1 down in the third to edge the former Top 10 player, and No.3 seed Sara Errani beat Elina Svitolina, 62 63.
Errani leads Cornet in their head-to-head, 3-1, winning their last three in straight sets.