Andy Murray took great heart from the fact he beat Kei Nishikori at Roland Garros on Wednesday without displaying his best form.
For the fourth year in succession, Murray is through to the last four of the French Open, his latest passage to the semi-finals coming courtesy of a four-set victory over Nishikori on Court Philippe Chatrier.
The world number one got off to a poor start against the eighth seed, but ultimately won with a degree of comfort, triumphing 2-6 6-1 7-6 (7-0) 6-1.
Murray, who will now face 2015 champion Stan Wawrinka in a repeat of the semi-final match-up he won last year, said: "I didn't feel like I played great tennis. It's a huge step in the right direction for me.
"Anyone can win matches when they are playing well. It's winning when you're not playing your best is more impressive. So I'm happy about that."
At 1-1 and deuce in the second set, Murray lost a first serve in controversial circumstances as he was handed a second time violation warning by umpire Carlos Ramos during his ball toss.
A fired-up Murray duly reeled off five games in succession to win the set and level the match, but the Wimbledon champion did not feel his run-in with the official had a huge influence.
"Obviously for a couple of points after that I was fired up, because I was frustrated at that moment. It felt to me like it was a strange decision," said Murray.
"I have never seen anyone get a warning after they have missed the ball toss. I have never seen that. So I was frustrated about it, but I don't know how much impact that had.
"It's not like I played a great point the next point. Kei missed a second-serve return, and then I think a good serve on the next point. Obviously, I broke the following game. Kei played a poor game to [allow me to] break.
"I didn't do anything special, but that was a critical period of the match, because he started way better than me. He had chances [at the] beginning of the second, as well. And then from there I started to do a bit better."
Nishikori acknowledged that a lack of consistency led to his downfall.
"I couldn't maintain my level, obviously," said the Japanese.
"I was missing a little more in the end than earlier in the match. I think a little bit of rushing too much, [and I was] too aggressive sometimes. At the same time he was raising his level, so it was tough to play in the end."