World number two Roger Federer recovered from a shaky start to see off Kristof Vliegen and hand Switzerland a 2-0 lead over Belgium in their Davis Cup playoff tie on Friday.
The US Open champion was forced to a tie-break in the first set and went 3-0 down in the second before recovering to win his singles rubber 7-6, 6-4, 6-2.
"I was worried going into the first set tiebreak, I was worried midway through the second set," Federer told reporters.
"I always thought if my game comes together from the baseline, then I would always be the overwhelming favourite and that is exactly what happened."
Stanislas Wawrinka earlier defeated Belgium's Steve Darcis 6-7, 6-1, 6-3, 2-6, 6-4.
Australia, champions 28 times, found themselves 2-0 down away to Chile after a dismal first day in Antofagasta.
Nicolas Massu shrugged off his poor recent form to beat Chris Guccione 7-6 (7-4), 7-6 (7-5), 3-6, 7-6 (7-2) in just under four hours before Fernando Gonzalez beat Peter Luczak 6-2, 6-2, 6-3 in a fraction under two.
Andy Murray swept aside Alexander Peya in straight sets to level against Austria, after Jurgen Melzer had fought back from one set and 4-1 down to beat Britain's Alex Bogdanovic in the tie's first rubber.
Murray, the world number four after reaching the US Open final, signed off with a choking gesture in a response to pre-match comments from Melzer.
"I was told I wasn't going to handle the pressure very well but Jurgen (Melzer) was the one who struggled a little more than me today," Murray said on court after the match.
World number three Novak Djokovic set Serbia on the way to a 2-0 lead over Slovakia with a straightforward 6-2, 6-4, 6-3 victory over Dominik Hrbaty before Janko Tipsarevic came from two sets behind to beat Lukas Lacko 6-7 (3-7), 4-6, 6-4, 7-6 (7-5), 8-6.
Croatia established a commanding lead over Brazil after Mario Ancic and Ivo Karlovic beat Thomaz Bellucci and Thiago Alves.
India will have to win all three remaining rubbers if they are to progress after Victor Crivoi and Victor Hanescu both won convincingly to give Romania a 2-0 lead.
Peru and South Korea finished the day level in their ties against Israel and Netherlands respectively.
In the doubles rubbers on Saturday, Switzerland's Olympic doubles champions Federer and Wawrinka could reunite against Belgium while Britain coach John Lloyd must decide whether to pair Andy Murray with brother Jamie against Austria.