From crying in despair to weeping with joy, all in the space of 10 points.

What an emotional rollercoaster this was for Harriet Dart. And what a win for the 27-year-old against her old foe Katie Boulter in a truly epic Battle of Britain.

Three times Dart was reduced to tears on No 1 Court on Thursday. 

And yet somehow Dart was able to dry her eyes, regroup and turn the tiebreak around. The world No 100 managed to win eight of the last 10 points to take the thrilling breaker 10-8, with tears flowing again as she dropped to her haunches in disbelief following her remarkable 4-6, 6-1, 7-6 victory.

‘I wear my emotions on my sleeve, so you see everything I am thinking,’ admitted Dart after beating Boulter for just the second time in their eight meetings.

‘My head-to-head is absolutely woeful against Katie, so I wasn’t expecting too much. 

‘But even though I was down in that tiebreak, I thought just, “Give it everything and have no regrets”.

‘I am really happy to have battled my way through. 

‘It was so nice to get my first big win on a really big stadium court in front a home crowd. It’s really surreal.’

To her credit, Boulter was magnanimous in defeat, hugging her Billie Jean King Cup team-mate at the end of a clash which had been billed as a grudge match given the fiery nature of their previous encounters.

Last year, when Boulter celebrated victory in the Nottingham Open quarter-finals by pointing to her head in reference to her mental strength, Dart had snapped: ‘I know you’re doing it towards me. It’s not professional.’

Then, when they met at the same venue last month, Dart lost her cool, labelling the umpire ’embarrassing’ and betting her £50,000 that she was correct about a disputed line call.

But on Thursday at Wimbledon, the pair let their tennis do the talking, thrilling the No 1 Court crowd in a topsy-turvy tussle which lasted almost three hours.

British No 1 Boulter, who is ranked 71 places above her rival, had predicted an ‘absolute battle’. Yet there was little sign of it being one when she broke Dart’s third service game and saw out the first set 6-4.

However, in front of her boyfriend Alex de Minaur, who had rushed over from No 3 Court after crushing Jaume Munar in his own second-round match, the 32nd seed’s game inexplicably fell apart in the second set.

Dart raced into a 4-0 lead with a blistering forehand down the line, then whipped up the largely neutral crowd, urging them to get on her side. 

With her new-found support, the underdog sealed the set 6-1 and then went 4-2 ahead in the decider, before Boulter pegged her back to take it into a tiebreak.

The momentum was all with Boulter at 6-2 but she then crumbled, ballooning a forehand long for her 75th unforced error of the match which handed victory to Dart, who reached the Wimbledon third round for just the second time in her career. She will play China’s Wang Xiyu, who shocked fifth seed Jessica Pegula.

‘She was better than me today,’ admitted Boulter, whose only previous defeat to Dart was at the Kangaroo Cup in Japan six years ago. ‘I actually didn’t notice her crying. At 6-2 down, she’s got nothing to lose and she kind of just relaxed. I think I played into her strengths as well.

‘I wish her the very best. We’re Billie Jean King Cup team-mates. We’ve been through this long journey together. I hope she goes far in this tournament. These are the kind of losses that sting. But I’m going to use this tough moment to really spur me on. This time next year, I’m going to be a better player.’

Earlier, there was embarrassment for Lily Miyazaki who became the first Brit to be double-bageled at Wimbledon since Clare Wood in 1997. The 28-year-old wild card lost 6-0, 6-0 in just 50 minutes to Eastbourne winner Daria Kasatkina on Court 18.

Miyazaki won just six points in the first set – and only 19 in the entire match – in a humiliating defeat. ‘It was really tough,’ said Miyazaki, who later won her doubles match alongside fellow Brit Emily Appleton.

‘She’s a great player and I’m not used to playing at that level. When I got on to the court, I was a little nervous. I never settled in. When you have those nerves, your feet don’t get going. Your arm is tight. It was just a nice lesson that I got.’