Novak Djokovic was at a difficult point in his career when he was confronted by Tomas Berdych at the semi-final stage of Wimbledon three years ago.
But the man who has risen to No 1 in the world believes the defeat that Berdych inflicted that day provided the catalyst for his success.
Just two years after he won the 2008 Australian Open, people had begun questioning whether Djokovic's best days were already behind him.
How wrong they were. Belief, drive and the masterstroke of switching to a gluten-free diet have helped him soar to the top of the men's game. The Serb, now 26, has won five Grand Slams since and is aiming to add another Wimbledon title to the one he secured in 2011.
Djokovic approaches his Court One quarter-final against Berdych as the firm favourite, but he is wary of the Czech's threat, particularly given his memories of their last meeting.
"I had quite a turbulent five, six months of 2010," Djokovic said. "The semi-finals of Wimbledon came at the right time for me because I felt that was like a springboard for me.
"From that moment on everything started going uphill really. I didn't play great in that match against Tomas, but credit to him because he got to the final that year, and he beat Roger [Federer] and myself, played a good match against Rafa [Nadal in losing the final].
"So he knows how to play on grass. That's the only time we played on this surface. I'm expecting a difficult match.
"It's the quarter-finals of a Grand Slam. He's an established top-five, top-10 player in the world. We're going to go for the win, both of us."
Berdych is bidding to reach a fourth Grand Slam semi-final by beating Djokovic, a player he overcame when they met at the Rome Masters in April. The winner of their clash will face David Ferrer or Juan Martin del Potro in the semi-finals.