World number two Roger Federer survived a scare to beat fellow-Swiss Stanislas Wawrinka 2-6, 6-3, 6-2 on Friday to reach the semi-finals of the Stockholm Open.
Federer had his serve broken by the fifth seed in the first game and seemed out of sorts until the fourth game of the second set when a smashed winner signalled the start of his comeback.
"Things happen really quick in three-set matches and Stan got off to a flyer," the top seed told Swedish TV.
"I struggled with my rhythm a little bit.
"Everybody expects me to win, sometimes it's not easy. I thought he played fantastic.
"He was dominating me there for a while so it was hard. I was just trying to hang in there," added Federer.
Earlier, second-seeded Swede Robin Soderling was beaten 7-6, 6-1 by Germany's Florian Mayer in a big-serving battle.
Mayer next faces Jarkko Nieminen after the Finn put out American James Blake 6-0, 6-2.
Federer takes on fourth seed Ivan Ljubicic after the Croat defeated countryman Ivan Dodig 4-6, 6-2, 6-4.
