By Simon Evans
LONDON (Reuters) - Croatian Marin Cilic reached the Wimbledon semi-finals for the first time with a five-set win over Luxembourg's Gilles Muller on Wednesday and said he now had real belief in his ability to go all the way.
Cilic won his only grand slam title at the U.S. Open in 2014 and has been in the last eight at the All England Club for four straight years.
Now he will face American Sam Querrey for a place against Roger Federer or Tomas Berdych in Sunday's final after beating Luxembourg's Muller 3-6 7-6(6) 7-5 5-7 6-1.
The seventh-seeded Croat said his triumph three years ago at Flushing Meadows transformed his confidence levels.
"I would say winning the U.S. Open has helped me for all these grand slams I have played so far, and I believe the rest of my career," he said.
"Preparation-wise I believe in my own abilities. I believe when coming to these stages of the tournament, I'm going to still be able to play great tennis. I know I have it in me that I can win. That's extremely important," he said.
The 28-year-old said he had found a new focus that had enabled him to approach each contest in the right frame of mind.
"I think an extremely important part is to be mentally fresh, mentally ready. It's a matter of a few points here and there that can make a huge difference.
"I believe these last couple of months with being really mentally focused every single match has helped me to get to the point where I'm a little bit stronger mentally. I believe that can make a huge difference," he said.
Cilic was seen by many observers, including seven-times Wimbledon winner Federer, as the one player from outside the top five who could be a real challenger this year at Wimbledon and that appears to have also boosted the Croat's morale.
"It's great for me to hear that even he, and a lot of players around, even ex-players, when they were looking before the tournament started, that they were seeing me as a player that could go quite deep (into the tournament)," he said.
"That had given me a little bit more belief, a little bit more confidence that players and people around are also seeing that I'm in a great form, that I'm able to do great things.
"I think that just gave me a little bit more reassurance in myself, and obviously a great power that I managed to get to that level."
Querrey's five-set win over Britain's top seed Andy Murray on Wednesday was only his second appearance in the last eight of a grand slam after he reached that stage at Wimbledon last year.
Cilic believes 24th-seeded Querrey's lack of experience on the biggest stage could have a slight impact.
"Sam hasn't been at this part of the tournament... maybe that can have a small part in playing that match. But I don't think it's going to matter big-time," he said.
(Reporting by Simon Evans; Editing by Ken Ferris)