On an emotional day for British tennis, when Andy Murray could well have played the last competitive match of his illustrious career, Katie Boulter wrote her own page of history by becoming the first player to win the first-ever contested 10-point match tiebreak at the Australian Open to defeat Ekaterina Makarova and reach the second round.

I was in the moment and I kind of forgot that it was first to 10, but I'm happy I could dig deep and get through it in the end, Katie Boulter

Celebrating a bit too early in the epic three-setter, Boulter thought she had won the match when the tiebreak went to 7-4, forgetting the new rules which meant she needed to reach ten points.

The extended tiebreak format is in use for the first time in singles at any Grand Slam championships.

Reminded the tiebreak was a first-to-ten-points affair, the British No 2 re-grouped to win it 10-6 and was later able to see the funny side.

The World No 97 managed to regain her composure to complete an impressive 6-0 4-6 7-6(6) win over the 2015 semi-finalist from Russia.

“I was in the moment and I kind of forgot that it was first to 10, but I’m happy I could dig deep and get through it in the end,” Boulter, who plays eleventh seed Aryna Sabalenka of Belarus in the second round, told Eurosport.

“I’ve got to take it light-heartedly. I ended up getting the win, I probably would have been really devastated had I not.”

Boulter was one of seven Britons in action on the opening day, across the women’s and men’s draws, but Harriet Dart and Heather Watson both fell to heavy first-round defeats in the sweltering heat.

It was a thrilling victory for the 22-year old Londoner, though, who is making her first appearance in a main draw of a Grand Slam outside of Wimbledon, and put in a solid performance.

She blitzed her way through the first set against the Russian with some impressive power hitting off her forehand, but lost the second set before fighting out the tense decider.

Although the experienced Russian fought back, Boulter held her nerve in the final set to force the match breaker and then moving 5-0 up as frustration brewed at the other end of the court, with Makarova being handed a code violation for an audible obscenity.

Hitting 53 winners during the contest which lasted almost two-and-a-half hours, Boulter registered her first main draw singles victory at a major outside of last year’s Wimbledon.

The British No 2 arrived at Melbourne Park on the back of securing a deal with David Beckham’s and Neymar’s agent, Simon Oliveira, having entered the top 100 late last year.

Her next opponent, the 11th ranked Belarusian hotshot Aryna Sabalenka, thrashed Anna Kalinskaya 6-1 6-4 in quick fashion, and it will be a sterner for her on Wednesday.

Heather Watson gets checked out by the doctor

Heather Watson, who is now 26 and was replaced by Boulter as the British No 2 on Monday, succumbed to a 6-1 6-2 defeat against 31st seed Petra Martic to become the first woman to leave the Australian Open after 64 minutes of play.

The World No 108 has now suffered a first-round exit at each of the last three Grand Slams and is struggling to find the form that took her to a career high ranking of No 38 in the early part of 2015.

“I have been feeling anxious, wanting to do well,” admitted Watson afterwards. “It was hot out there and you cannot be tense.

“I felt faint and a bit dizzy on court,” added Watson, who called the doctor to the court early in the second set to check her blood pressure.

“It’s not the first time it has happened. It happens quite a lot, especially in these conditions and when it’s high stress.

“I cannot continue like this. Tennis is lots of ups and downs. At the moment it’s not clicking. I didn’t enjoy that,” she concluded, breaking down in her press conference.

Maria Sharapova shakes hands with Harriet Dart following their first round meeting

Harriet Dart probably didn’t enjoy her outing, either, on the Rod Laver Arena facing Maria Sharapova.

Dart won three matches to qualify for the season’s opening Grand Slam but was unable to offer any test for the 2008 champion in the day’s opening match.

The 22-year-old struggled under the spotlight, winning only 24 points of the 84 played, in a comprehensive 6-0 6-0 defeat against the former World No 1 that took 63 minutes.

It was a big ask for Dart, coming through qualifying to playing a fit and focused Sharapova on the huge arena, and she was unable to respond well to the occasion.

There were tears as she left the court but she composed herself well enough before entering the interview room.

“It was always going to be a difficult match, especially on such a big court,” Dart observed.

“She’s got a lot more experience than me but I came through qualifying, so that’s something to be positive about.

“I think I carried myself well out there. I played all right and won more points than I thought I had.

“I was just unfortunate not to get on the board but this happens. Next time I’ll be a bit more prepared.”

Sharapova moves on to play Rebecca Peterson of Sweden, who defeated Romania’s Sorana Cirstea, 6-4 6-1.

The Russian, a winner at Melbourne Park in 2008, said she was feeling positive after ‘tough times’ in her career, saying: “I love what I do, I love competing and challenging myself to get better.

“The youngsters are coming up and they’ll eventually take our place but not just yet, we want a little more time.”

The former World No 1was far from perfect, committing 3 double faults and 8 unforced errors, but was never threatened by Dart, who made a hesitant start against her childhood idol.

Sharapova pounced on the Briton’s weak second serve to repeatedly break her opponent, bringing up the first set bagel after 31 minutes.

The second set followed the same pattern, with Dart finally put out of her misery trying to save match point when she hit a return wide despite having an open court before her.

“Despite my opponent not having the best day, you still have to get the job done,” Sharapova concluded.