Back to level par for the tournament goes Lottie Woad. The 20-year-old is on the 12th with a short par putt but she's berating herself after missing it.

She is three shots ahead of Spain's Julia Lopez Ramirez in the battle to be low amateur and that has to be her focus on this tricky closing stretch.

BOOM!

Our first birdie from the final pair. Inside 10 foot and no mistake from Jiyai Shin.

Back to the outright leader.

Jiyai Shin rattles her second shot right up to the pin. A first proper look at birdie today. Is now the time to move?

Another chance goes begging for Lydia Ko. The ninth, which plays 322 yards and is no more than a controlled drive and wedge in to the flattest green on the course, is a big birdie chance but she can't drain a 20-footer.

A slight flicker of emotion before she walks the short distance to the 10th tee and pulls her drive down the left into the wispy grass.

Gorgeous soft chip from Jenny Shin on the par three, who would have been disappointed with her tee shot. Likewise, Nelly Korda hits a well-weighted long putt up to gimme range.

But Shin misses her 10-footer for par, that would have been a brilliant recovery.

In our completely unscientific straw poll from earlier, the vast majority of people think the winning score is going to be better than six under par (see 15:39)

That's bad news for Akie Iwai, the Japanese who has set the clubhouse target after a three-under-par 69 today.

Her round featured five birdies as she improved her score to two under.

A number of players have been driving the ninth green during the course of this week - England's Georgia Hall had a sensational eagle two in round one - but the wind is not really helping today. It's more across and slightly into the face.

Lydia Ko stings a low one up the middle and then flicks a wedge in to around 20 feet. Another birdie chance coming up for the Olympic champion who last won a major eight and a half years ago.

Nelly Korda bangs it into the cup, picks it up and moves on. A birdie after a bogey is what all the great champs do.

Her approach shot meant that wasn't going to be missed.

Back to co-leader she goes.

I know it's a bit breezy out there and the pace of play is often slow at the Old Course because of the double greens, the tricky section where the course loops around at the far end and seven and 11 cross fairways, but two hours for the opening six holes is, frankly, ridiculous.

But that's what our final pair have achieved. Yes, it's not completely their fault given they had a 20-minute wait on the fifth tee but is nobody ahead of them on the clock?

Hopefully they'll speed up a bit on the back nine or else we'll be running out of daylight!

More long birdie attempts for Jiyai Shin and Lilia Vu. You wonder if they are happy with six under par and are just going to play the percentages from here.

Giving yourself long two-putts though is dangerous.

No problem for Shin, who smacks it up the hill to gimme range, unreal!

Vu does the same from the other side of the flag. Steady and sensible golf in the conditions.

Lydia Ko is on the eighth green, studying a 20-foot birdie putt to move into a share of the lead. She strikes a decent putt but the ball bobbles a couple of times and that affects the pace.

Par and remains one back.

Ruoning Yin set the pace early on day one but was unable to back up her four-under 68 on days two and three. But the Chinese is suddenly threatening the top of the leaderboard again after her second birdie of the day, on the ninth.

Nelly Korda will be kicking herself after a bad miss from seven foot. Meanwhile, after a pin-point approach, Jenny Shin shows her how to sink from a similar range - if not longer - to walk away with back-to-back birdies.

What a response after her double bogey.

Jiyai Shin and Lilia Vu both will be disappointed with their approaches. A birdie is very much doable on this hole - as proven by Nelly Korda and Jenny Shin.

Two long birdie attempts come up short. Shin pushes her slightly, but is able to tidy up from six foot.

The smile returns to Lottie Woad's face as she bounces back from her untidy double at eight with a birdie at the short par-four ninth.

She's out in a one-over 37.

Both Jiyai Shin and Lilia Vu pull their second shots at the par five to the right, but they will be okay. It makes their second shots much tougher to get a look at birdie.

It also shows how wonderful Nelly Korda and Jenny Shin hit their shots just before them.

There has been a bit of a backlog on this hole, that delay wouldn't have helped the pair, who were waiting for around 20 minutes before playing.

I've not been lazy, they haven't been playing!

Is that a tear Lexi Thompson is wiping from her cheek as she strides up the 18th fairway for perhaps the last time in a Women's Open. It's certainly her last at St Andrews.

The American announced a couple of months ago that she would retire at the end of the year, although she is qualified to play some of the majors in 2025.

She famously qualified for the US Women's Open at the age of 12, turned pro at 15 and won what has turned out to be her only major at the age of 19.

The 29-year-old is hoping for one last crack at the Solheim Cup next month but will need a captain's pick to make the US team.

Thompson stopped atop the Swilcan Bridge for the obligatory photo and farewell wave to the fans. She then found the green with her second but three-putted from 25 feet for a scruffy bogey finish.

Nelly Korda hammers her second shot on the par five to give herself a massive eagle attempt. She smashes her put from at least 100 foot to give herself a great look at birdie.

You don't usually see putts that long, the uniqueness of St Andrews!

Jenny Shin nails a 17-footer for birdie. Korda takes note and hammers in her second putt from inside 10 foot to move into the co-lead.

The home challenge is done. English amateur Lottie Woad was the last woman standing in that respect but a double-bogey five on the par-three eighth has done for her chances.

The 20-year-old ended up in a bunker off the tee and had to chip out sideways. Time to refocus and concentrate on securing the low amateur prize.

South Africa's Casandra Alexander is the epitome of never giving up.

The 25-year-old was four over after five holes in round one. She's now three under heading into the back nine and just three off the pace after successive birdies on eight and nine.

There always seems to be one who creeps up out of nowhere.