Defending champions Watson and Henri Kontinen overcame the second seeds Bruno Soares and Elena Vesnina on Court One, with a 6-4, 6-7 (6/8), 6-3 victory, setting up a clash with Murray and 22-time grand slam winner Martina Hingis.
In a commanding Centre Court performance, Murray and Hingis beat Brazilian Marcelo Demoliner and Spain’s Maria Jose Martinez Sanchez 6-2, 7-5 to justify their status as the top seeds.
Murray, who was a champion alongside Jelena Jankovic ten years ago, was not intending to play mixed doubles at Wimbledon until Swiss great Hingis asked him.
The proposal from the 36-year-old, who won the women’s singles title 20 years ago, was one Murray did not hesitate over.
“I haven’t really played that much in the last couple of years but for me it was a great opportunity to play with Martina,” Murray said.
“She’s an amazing player and has shown that all this week and I’m really glad I decided to play. It’s great to be in a grand slam final and I’m really looking forward to it on Sunday. It’ll be a great occasion for us.”
And Murray would love their partnership to continue in future grand slams.
“I hope so, from my side,” Murray said. “If you’ve got a great partner it makes it easier to commit to.”