Laura Robson produced a stunning fightback to beat Marina Erakovic and become the first British woman to reach the last 16 at Wimbledon since 1998.
The British number one was three points from a straight-sets defeat on Court Two, but recovered to win 1-6 7-5 6-3.
Robson, 19, will face Estonia's former quarter-finalist Kaia Kanepi in Monday's fourth round, which will also see Andy Murray play Mikhail Youzhny.
It will be the first time since Sam Smith and Tim Henman made the same stage in 1998 that there has been British interest in both the men's and women's singles at the start of the second week of Wimbledon.
Robson is through to the last 16 at a Grand Slam for the second time, following her breakthrough at last year's US Open.
The former Wimbledon junior champion looked on course for a swift and disappointing defeat when she dropped the first set in just 22 minutes.
Erakovic, 25, was serving superbly and broke for a third time to move 3-2 up in the second set, but with victory in sight the New Zealander began to falter.
A double-fault by the world number 71 when serving for the match opened the door for Robson, who hammered a forehand winner to level at 5-5.
Two games later it was Robson pushing hard for the set and, after a Hawk-Eye challenge helped the Briton out, Erakovic double-faulted once again to see her lead disappear.
Robson was on a roll, winning eight straight games to move 4-0 clear in the decider, while the first-set form that saw Erakovic make just one unforced error seemed a lifetime ago.
There were nervous moments when Robson's run ended with a break, but the teenager played with real guts to cling on to her serve in the closing stages.
Roared on by the Court Two crowd, she battled her way to match point and fired a brilliant forehand down the line to clinch victory, before hugging her good friend Erakovic at the net.
"I was getting my butt kicked basically," Robson told BBC Sport.
"I was really struggling to return her serve. I just tried to work as hard as possible and stick with it until she started to get nervous, and that's what happened.
"The crowd were amazing. I'm so so happy to get through but definitely couldn't have done it without them.
"It's only my second time in the fourth round of a Slam. I'm looking forward to doubles tonight and then to Monday."
Robson is now guaranteed to move into the world's top 30 when the rankings are updated after the tournament, becoming the first British woman to do so since Jo Durie in 1987.
"It's a good thing, hopefully this means I'll be seeded for US Open," said Robson.
"But I don't go into the match thinking, 'If I win this, I'm going to be top 30.'"
Robson came out later to play women's doubles with American veteran Lisa Raymond but the pair lost 6-4 6-4 to seventh seeds Anna-Lena Groenefeld of Germany, and Kveta Peschke of the Czech Republic.
Meanwhile, British duo Dominic Inglot and Johanna Konta enjoyed a memorable doubles victory as they won a thrilling 36-game deciding set.
In a first-round match which lasted just under three hours, the home pair got the better of Nicolas Almagro and Maria-Teresa Torro-Flor 4-6 6-3 19-17 on Court 12.
It was a second success of the day for Inglot, who had already combined with Philippines player Treat Huey to beat Andre Begemann and Martin Emmerich.
Last year's men's doubles champion Jonny Marray also won twice.
The Sheffield man, and new partner Colin Fleming, is into the third round after a 6-3 6-4 7-6 win over Frantisek Cermak and Michal Mertinak, before he and Heather Watson joined up to see off Robin Haase and Alicja Rosolska.
Jamie Murray and Australian partner John Peers were knocked out in the first round of the men's doubles. Murray's mixed doubles match with Hsieh Su-Wei was abandoned for the night because of fading light, as they faced a 5-3 deficit in the deciding set against Jean-Julien Rojer and Vera Dushevina.