The Katie Boulter and Johanna Konta show continued in the Fed Cup as they booked Great Britain's place in the Europe/Africa Zone Group 1 play-off against Serbia on Saturday.

The British pair both won their third successive singles match of the week in Bath to hand their country a victory in the winner-takes-all Pool A tie against Hungary.

They had to show all of their brilliant fighting spirit as they won three-set marathons, having both been a break down in the deciding sets.

Boulter had to battle hard past Dalma Galfi winning a deciding set tie-break, while Konta, who looked like she was going to enjoy a much easier affair against Anna Bondar, was faced with the same task as the hosts eventually won with a rubber to spare.

Despite their exertions over the last three days, illness to Heather Watson and the relative inexperience of Katie Swan and Harriet Dart means they are both now likely to again lead Anne Keothavong's side against Serbia on Saturday afternoon, where victory will earn them a spot in the World Group II play-off in April.

Boulter is particularly enjoying her role as leading lady as her Fed Cup singles career has got off to a brilliant start.

She took her record to 3-0 with a tense 6-4 6-7 (5) 7-6 (1) win over an opponent ranked 311 in the world.

Konta was expected to dispatch Bondar, ranked 224 in the world, much easier, especially after she coasted to the first set.

But Bondar played some "lights out" tennis which left Konta needing a deciding-set tiebreak to win, eventually posting a 6-2 6-7 (1) 7-6 (4) success in two hours and 42 minutes.

Konta, who also played close to three hours on Thursday, said: "She played lights out for a big part of the match and it was hard to be end on receiving end of it.

"She didn't drop her level like I expected her to after a period of time. She realised she had nothing to lose and she brought her game and that was difficult to be the end of it, I am happy I was able to counter it and get through.

"The energy levels are as good as they can be."