Maria went an early break up in the first set, drawing errors out of Anisimova, before a thumping backhand winner from the American put it back on terms.
However, Maria kept Anisimova on the move, visibly frustrating her, and a netted forehand gave Maria the break back, before she served out the set with ease.
The numbers told the story, with Anisimova committing 10 unforced errors to Maria's three in the opener, and the momentum stayed with the German as she broke at the first chance in the second set.
A mammoth fourth game saw seven deuces and Maria saving two break points for 3-1, before a brilliant scamper to a drop shot in the next allowed her to go a double break up.
Anisimova, who won the WTA 1000 title in Qatar earlier this year, went for broke, pummelling her shots to rescue a break and keep in touch.
But Maria, backed by the packed crowd, kept her nerve to serve out to 30 and secure her place in Queen's history.
Maria is due to compete at the Nottingham Open, which begins on Monday, but said she will celebrate with her family first.
"This doesn't happen every week so we have to celebrate with something," she added.
"I think the kids will probably want some crepes with Nutella!"