From the very moment the Australian Open began, Andy Murray and Roger Federer have been silently matching each other, set for set.
Neither has lost one yet, and tomorrow the two men will bid to set up what is expected to be a classic semi-final.
The Scot takes on Jeremy Chardy of France, about as good a draw as he could have hoped for, having yesterday cruised past another Frenchman, Gilles Simon, 6-3, 6-1, 6-3.
Second seed Federer meets Jo-Wilfried Tsonga, having outclassed Milos Raonic of Canada 6-4, 7-6, 6-2 last night.
Both men are too experienced to let their straightforward starts make them think that the next one will be easy, but they will be equally delighted that they have avoided the kind of five-hour marathon that defending Aussie champion Novak Djokovic came through in round four.
"Some Slams I've started off really, really well and some I have had some tough patches in," said Murray.
"Sometimes at the Australian Open I've started really well and got through to the second week without dropping a set. It doesn't really matter – Roger hasn't lost a set either yet, and I'm sure will be happy with where he's at.
"You just have to wait and see whether you're ready to up it when the time comes, but I hope I will be ready."
Murray admits he would like a night match to get used to the often cooler conditions in the evening. The semi-finals and final will both be played in the evening, but his quarter-final may well still be in the daytime, with Federer and Tsonga perhaps more of a box-office draw.
"Ideally it would be nice to get a match in the evening but if not you just get on with it," he said. "Sometimes the schedule works well for you and sometimes it doesn't.
"You just try and play and deal with everything as best you can. When you do play in the evening, the conditions feel fine.
"Just the thing you need to get used to is the timing of the ball and the speed of the courts. They change when it's dark."
Speaking about yesterday's win, Murray added: "After the first few games it didn't feel that competitive. At this stage of a Grand Slam you're geed up and prepared for a tough battle.
"You're not necessarily feeling pressure, but you're wanting to try to finish the match as quickly as possible."