The home hope found herself overmatched against the second seed from the off as Bertens surged into a 4-0 lead before a third break sealed the first set.
A break to cut the gap to 3-2 in the second proved a false dawn for Kudermetova, who failed to win another game after that as she was beaten in under an hour.
Another Russian, qualifier Anastasia Potapova, is up next for Bertens.
Third seed Petra Kvitova found the going somewhat tougher before prevailing 7-6 (7-1) 1-6 6-2 against Alison van Uytvanck in two hours and 16 minutes.
"Definitely, it was a tough one," Kvitova said, following a match featuring a remarkable 33 break-point opportunities.
"I’ve never played Alison before, and she'd already played one match on the surface, and for me it was the first one, so that's always a bit challenging."
Kvitova must now take on the in-form Ekaterina Alexandrova.
The Russian claimed her ninth straight win indoors as she beat seventh seed Donna Vekic 6-1 7-5, while Maria Sakkari was also a straight-sets winner over Alize Cornet.
At the Thailand Open, top seed Elina Svitolina made short work of Storm Sanders, blowing away the qualifier 6-1 6-2 in 57 minutes.
Magda Linette was a 7-5 6-1 winner against the experienced Peng Shuai in blustery conditions and has further Chinese opposition coming up after Wang Xiya defeated Barbara Haas 6-3 6-4.
Romania's Patricia Maria Tig also reached the quarter-finals in straight sets at the expense of sixth seed Yafan Wang.
World number eight Bertens defeated teenage qualifier Anastasia Potapova 6-4 7-6 (7-3) having staved off three set points in a second set in which she was 5-2 down.
Bertens will face Ekaterina Alexandrova next after she was handed a walkover when third seed Kvitova withdrew.
Top seed Belinda Bencic was ousted by Maria Sakkari in three sets, with Elena Rybakina beating Oceane Dodin in the other quarter-final.
At the Thailand Open, world number four Elina Svitolina suffered a surprise straight-sets loss to Nao Hibino, who was joined in the semi-finals by Magda Linette, Patricia Maria Tig and Leonie Kung.
Bertens became the first player to win back-to-back titles in St Petersburg, easing to a 6-1 6-3 victory over eighth seed Rybakina.
World number eight Bertens, who was due to face the returning Kim Clijsters in the first round of the Dubai Tennis Championships before withdrawing this weekend, was in tears after losing just one set this week to claim a 10th WTA title.
She saved all five break points she faced, securing a first title this year.
"I never expect any match to be easy. It didn't feel easy, of course, even though the scoreline was. At the end, I felt a little bit nervous, but I was just happy to close it out," second seed Bertens said.
"I just tried to approach every point the same, no matter what the score is. Sometimes, on a break point, you go for a little more on serve, and that's what I did today."
Linette sealed the second WTA Tour title of her career with a 6-3 6-2 defeat of qualifier Leonie Kung in Hua Hin.
Teenager Kung, playing in the main draw of an event at this level for only the second time, failed to break Linette's serve and was made to pay for being unable to hold on three occasions.
World number eight Bertens, who has been confirmed as Kim Clijsters' first opponent in next week's Dubai Tennis Championships, required a decider on Saturday to secure a third successive win over a Russian opponent.
But despite relinquishing control in the second set, Bertens did not let up in the third as she ultimately cruised through to reach her first singles final since October.
Eighth seed Elena Rybakina will be Bertens' opponent in the final, with the 20-year-old advancing to the biggest final of her career so far with a 3-6 7-5 6-1 defeat of Maria Sakkari.
Elsewhere, in the Thailand Open, teenager Leonie Kung got the better of Nao Hibino to make the final in what is just her second WTA Tour main draw event.
The 19-year-old had to come from a break down in the decider on Saturday but ultimately triumphed 7-5 4-6 6-3.
Kung will face world number 42 Magda Linette in the final, with the Pole having overcome Patricia Maria Tig in her semi-final.
Having gone out in the first round at the Australian Open earlier this month, former world number one Muguruza did the same in France, suffering a resounding 6-1 6-4 defeat to 18-year-old Czech qualifier Noskova.
Third seed Cornet did not fare much better on home soil, capitulating after drawing level with Osorio as the Colombian triumphed 6-4 4-6 6-1.
The other seeds in action on day one at the WTA 250 event avoided the same fate, with fifth seed Anastasia Potapova beating Marina Bassols Ribera 4-6 6-1 6-2 and fourth seed Petra Martic fighting back to edge her two-hour battle with Kristina Mladenovic 3-6 6-3 7-5.
At the Thailand Open in Hua Hin, third seed Wang Xiyu was beaten in an all-Chinese meeting with Zhu Lin, while Wang Xinyu triumphed in straight sets against Joanne Zuger and Ukraine's Lesia Tsurenko eliminated Ysaline Bonaventure.
