Murray thanks coach Ivan Lendl

But after a disappointing start to the season, reuniting with his mentor three days before the start of the French Open has coincided with an upturn in form, with increasingly impressive performances helping Murray to cruise to today’s quarter-final against Kei Nishikori.

Before the tournament, Lendl spent only the four matches at the Australian Open in Murray’s box, leaving him to flounder through the clay-court season to what is statistically the worst start to the season this century by the world No1.

However, Lendl was able to diagnose quickly the problem and from day one here set about taking the 30-year-old back to the fundamental process of hitting a tennis ball.

“A lot of the time when things are not going well you start over-thinking things,” Murray said.

Then once you start to do that, you get through a couple of matches and you start feeling better.

This time, to the same stage, Murray has spent nearly an hour less on court, including rolling over his last two opponents in straight sets.

“I got lucky last year that I ended up playing John Isner and Ivo Karlovic back-to-back which were not physical matches really after the first couple of rounds.

Ivan Lendl watching Andy Murray in the French OpenGETTY Ivan Lendl has helped Andy Murray get back to basics The world No8 has played two more sets than Murray and was forced to play three days in a row between Saturday and Monday.