* Czech holders race to 2-0 advantage over Japan in Tokyo
* Swiss 1-1 with Kazakhstan after Wawrinka's shock loss
* Italy lead Britain 1-0, Murray ahead before light fades
* Germany 2-0 up against France as Tsonga loses in five
By Toby Davis
LONDON, April 4 (Reuters) - Holders Czech Republic took a huge step towards the Davis Cup semi-finals by opening a 2-0 lead over Japan on Friday, while Roger Federer's Switzerland were locked at 1-1 with Kazakhstan in their quarter-final.
The fancied Swiss were given a scare when Australian Open champion Stanislas Wawrinka was upset in four sets by Kazakhstan's Andrey Golubev, ranked 64 in the world, 61 places below his opponent.
Federer rode to the rescue with a comprehensive straight sets demolition of Mikhail Kukushkin to leave the tie delicately poised ahead of Saturday's doubles.
Britain's double grand slam champion Andy Murray was involved in a dogfight with Italy's Andreas Seppi before bad light saw their clash suspended with the Wimbledon champion leading by a set.
His team, however, were trailing 1-0 in the tie after Fabio Fognini beat James Ward earlier in the day.
France got off to an embarassing start against Germany, who are without the injured Florian Mayer and Tommy Haas.
Arnaud Clement's team were 2-0 down at the end of the first day after Julien Benneteau and Jo-Wilfried Tsonga proved incapable of beating lower ranked opponents in Nancy.
World number 50 Benneteau took the first four games off 96th ranked Tobias Kamke, against whom he had a 3-0 record, but failed to build on his fine start and lost 7-6(8) 6-3 6-2.
Tsonga, ranked 12th in the world after a poor start to the season, then lost 5-7 7-6(3) 3-6 7-6(8) 8-6 to world number 119 Peter Gojowczyk.
France's hopes of staying in contention rest on Michael Llodra and Gael Monfils, who are set to play in the doubles against Kamke and Andre Begemann on Saturday.
It was an easier day for the dominant Czechs, chasing a third straight title, as wily veteran Radek Stepanek and big-hitting Lukas Rosol won their singles rubbers to put them in control in Tokyo.
Former world number eight Stepanek came from a set down to beat Tatsuma Ito 6-7(5) 7-6(5) 6-1 7-5 before Rosol survived a mid-match wobble to suppress 21-year-old Taro Daniel 6-4 6-4 3-6 4-6 6-2.
The 35-year-old Stepanek used his serve to good effect, hitting 18 aces, as he ground down the 146th-ranked Ito in three hours, 53 minutes.
"Sometimes you have days when you are not playing your best tennis but you always have to find a way through. Today was a day like that and I am very happy that I was able to bring the first point to our locker room," said Stepanek.
Rosol was in command after twice breaking Daniel's serve in each of the opening two sets, but the Japanese debutant refused to go out without a fight, bagging the next two sets to level the match at two sets apiece.
The Czech, who famously dumped Rafa Nadal out of Wimbledon in the second round in 2012, regained his composure to see out the match with two breaks in the deciding set.
In Geneva, Golubev got the better of a nervous-looking Wawrinka with an impressive attacking display, winning 7-6(5) 6-2 3-6 7-6(5) in three hours 14 minutes.
"I am really disappointed with myself, but I have to give credit to Golubev who was playing really good," Wawrinka said on the Davis Cup website (www.daviscup.com).
"He was really aggressive and he found a way to win the match. I was expecting more mistakes and was not aggressive enough, but I a need to accept it and be ready for tomorrow."
Federer ensured the day had a happier ending for the Swiss by easing past Kukushkin 6-4 6-4 6-2, ending the match in dominant fashion with a double break early in the final set.
The winner of the tie will face either Italy or Britain, with the Italians ending Day One with a slender advantage after Fognini beat Ward 6-4 2-6 6-4 6-1.
Murray was leading the second rubber 6-4 5-5 when fading light brought an end to play but not before the Briton was forced to save several set points in the nerve-jangling final game of the day. (Reporting by Toby Davis; additional reporting by Julien Pretot in Paris; editing by Ken Ferris)