Andy Murray and James Ward both won their opening singles matches to put Great Britain on the verge of victory against Hungary in their Europe/Africa Group Two third round tie.
Murray beat his part-time opponent Sebo Kiss 6-0 6-2 7-6 (7-3) at the Braehead Arena in Glasgow.
Earlier Ward overcame sickness to beat Attila Balazs 6-4 6-4 4-6 6-4.
If Great Britain win Saturday's doubles they will win promotion to Europe/Africa Group One.
Murray was cheered on by an enthusiastic crowd, bolstered by students from nearby Stirling University. And the world number four, who reached the semi-finals of all four Grand Slam events in 2011, taught Kiss a lesson in the opening set, winning it to love.
Kiss, who now studies law and plays tennis part-time, was soon two sets down, but fought back to make the third set competitive.
The Hungarian clawed his way into the set from 5-2 down to force a tie-break but Murray's superior experience saw him win the breaker 7-3 to finish off the match.
After the win, Murray said: "I thought he played very well in the third set. I started the match well but when he started to play better I started to make a few more mistakes. But it's good to have a 2-0 lead after the first day.
"He made the wrong decision going back to school. He should have kept on playing," he said of Kiss.
Ward's victory earlier was more hard-fought and more dramatic. The Briton broke Balazs' serve in the third game of the first set and went on to win it 6-4.
The Londoner had to leave to court when serving for the second set at 5-4 to be sick.
He returned to close out the set but after turning over on his ankle at the start of the third, Balazs took heart and raced into a 3-0 lead. Ward went off the court again, for treatment, but eventually lost the set 6-4.
With great encouragement from the crowd Ward showed great character to bounce back in the fourth set, retrieving a break of serve to lead 5-4 and then serve out for victory in three hours and nine minutes.
"I've never been sick [during a match] before so it was obviously strange but they said I had to come straight back on and play or I'd forfeit," said Ward.
"I'm playing for my country. You've got to keep going and you've got to keep fighting, even though it was difficult."
Saturday's doubles sees Britain's Colin Fleming and Ross Hutchins up against Balazs and Kornel Bardoczky.
Fleming and Hutchins reached the quarter-finals at the US Open last week, and at this years Wimbledon.