EMILY King made a sparkling Mitsubishi Motors Badminton Horse Trials debut - 25 years after her six-time Olympian mother won the event - as she moved closer towards possible Rio selection.

King, 20, is the youngest Badminton competitor this year, but she performed with a maturity beyond her years to threaten German master Michael Jung's overnight lead.

King will go into Saturday's pivotal cross-country phase in second place, just 2.4 penalties behind reigning Olympic and European champion Jung, who is also chasing a £240,000 Rolex Grand Slam jackpot.

And such was the quality of her display on 14-year-old gelding Brookleigh, that the Great Britain selectors will not fail to have taken notice only two months out from naming a four-strong team for Rio.

While Kitty King, Pippa Funnell and William Fox-Pitt are widely touted as leading contenders to fill three of those places, Emily King's Badminton masterclass came barely six months after she secured a fourth-place finish at the Pau four-star event in France.

And it also led a strong British charge on day two, with Francis Whittington (Hasty Imp) holding on to fourth spot, Dani Evans (Raphael II) and Izzy Taylor (Allercombe Ellie) in equal sixth and Oliver Townend (Black Tie) eighth.

"The horse can do a good dressage test, and he didn't do anything differently today from what he did in the warm-up," said King, whose mother Mary - a competitor at every Olympics from 1992 to 2012 - looked on.

"I am over the moon. Brookleigh was really good. I knew he was capable of doing such a test, but he has never been in such a big arena as that. He kept his cool.

"I want to do very well here. I am a very competitive person. Since Pau, and having a good result there, I knew he was capable of doing well.

"I really like the look of the (cross-country) course - it is nice and bold and attacking. The conditions are great, and hopefully if I attack it well, he will respond."

King's considerable intervention apart - she would be the youngest Badminton winner since a 19-year-old Lucinda Prior-Palmer in 1973 - the leaderboard retained much of its appearance following Thursday's opening salvos until late on Friday, but Jung still held on to pole position.

A stunning dressage score of 34.4 penalties aboard his London 2012 double gold medal-winning horse La Biosthetique-Sam means that Jung remains the rider to beat, especially given his trademark cross-country brilliance.

The Grand Slam is awarded to any rider who wins consecutive Burghley, Kentucky and Badminton titles. So acute is its degree of difficulty that the only rider who has accomplished it is Britain's Funnell 13 years ago. Jung, though, already has Burghley and Kentucky silverware in the bag.

Zara Tindall, meanwhile, made a solid return to four-star eventing after the former world champion posted a score of 48.0 penalties on High Kingdom that left them in 36th place, but less than seven penalties outside the top 10.

High Kingdom missed almost all of last season after suffering a freak stable accident just before dressage at the Rolex Kentucky event in America.

It means the horse has still to qualify for Rio, although that should be achieved at Badminton if Tindall and High Kingdom go anywhere near their usual level of performance this weekend.

"He was a little bit jolly in there, but it is better to be that way," Tindall said.

"He hasn't been in a proper arena for a year, so I am pleased with him. Some of his work was really good.

"There are bits we have got to work on, and he was a little bit fresher than he normally probably is, but you just have got to deal with what you get and make sure everything is accurate. Now, he can go and do the fun bit!"