The doubles experts had been solid the whole way through the tournament but the defending champions had battles in their last two rounds to get to this point.
The pairs exchanged breaks in the opening set before Murray and Hingis edged ahead. With Andy Murray rushing on to the grounds to see the final stages, the top seeds saved three break points on the Murray serve before a return in the net by Watson handed them victory.
Another Murray intervention sealed a second break for 4-3 and this time they served out when the Scot hammered away a smash. I think it's paid off but I'm a bit exhausted now. We had quite a few breakpoint chances.
She said: "Jamie left me hanging overnight".
"They're a really tough team".
The British-Finnish pairing were defending champions, having won a year ago as a scratch pairing, while Murray and Hingis were also playing together for the first time in this championships. Also, the mixed doubles saw two British players in Jamie and Heather go head-to-head in a Wimbledon final for the first time since 1961. Just got to keep it simple. "When you're on the court, too, we know where we stand, what we do, what we can expect from one another as doubles players". It was just a great opportunity for me to play and to really feel like you could do good things on the court and have a great shot to win.
"(Men's) doubles is obviously my biggest goal of the year", said former doubles number one Murray. "It's going to take something pretty special to potentially take my eye off the ball with it".
"But like I said, it was a great opportunity". SSE do more for their customers, providing access to exclusive sport and entertainment reward offers and they're giving customers the chance to win fantastic experience packages to this year's already sold out event.