Murray, who progressed to the quarter-finals in the singles competition earlier on Thursday, helped Team GB to a 7-5 6-7 10-7 win over the Czech pairing of Radek Stepanek and Lucie Hradecka.
The British duo were made to work for their victory and the 25-year-old Wimbledon finalist was happy to progress after playing twice in a busy day for the Scot.
"We did well to come through that. Obviously up in the second set and then they got back into it. Radek (Stepanek) started playing very aggressive,” he said.
“It was good to get through it. It was fun. Obviously a long day, but I enjoyed it.
"I knew when I went ahead with the mixed that there was going to be an extra physical effort and the days were going to be a bit longer, but you don't get to do this very often.
“For a mixed doubles match the atmosphere was unbelievable. I have played in some great atmospheres but it's not always like that.
"I don't play mixed often. That was the first time I played in a few years. It feels like you're playing for your country and that's why I wanted to play mixed – to play in atmospheres like that."
The pair will now face the Australian duo of Lleyton Hewitt and Sam Stosur and Murray is aware of the dangers they face.
"Lleyton's known for his singles but he's an excellent doubles player, he made the final of the mixed here years ago and he's won (grand) slam doubles before,” he added.
“Sam, before she started to focus on singles, was No.1 doubles player in the world, so they will be very, very tough."
Robson – the 2008 Wimbledon girls’ champion – is delighted to be teaming up with a player of the calibre of Murray.
“I loved it. I think mixed doubles is great,” said the 18-year-old. “I enjoy playing at Wimbledon and it's always good playing with someone as good as Andy. It's exciting for me.
"I always get more nervous in doubles because you're playing with someone else and you feel a bit more pressure to make balls for them but it was a lot of fun out there."
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