World Championships bronze medallist Lakshya Sen showed nerves of steel as he stunned defending champion Lee Zii Jia of Malaysia to book a maiden final berth in the All England Badminton Championships here on Saturday.

The 20-year-old Sen became only the fourth men's singles player after Prakash Nath, Prakash Padukone and Pullela Gopichand to reach the final after outwitting Lee 21-13 12-21 21-19 in a gruelling semifinal match that lasted one hour and 16 minutes.

While Padukone (1980) and Gopichand (2001) are the only two Indians to have won the prestigious event, Nath (1947) and women's singles player Saina Nehwal (2015) had lost in the final.

Sen has been in sensational form in the last six months. He secured his maiden world championships bronze in December, before winning his first Super 500 title at India Open in January and finishing runner-up at the German Open last week.

Sen, who had defeated Lee the last time they faced in an international tournament six years ago at the India International Series, showed great tactical acumen, athleticism and mental fortitude as he recovered from a mid-game slump to script history at the prestigious tournament.

Both the players knew each other's game well as they had sparring sessions as part of an exchange programme involving Prakash Padukone Academy in Bengaluru in 2016.

In the opening game, Sen showed great defensive skills and moved well in the court to eke out a 11-7 advantage at the interval.

Lee managed to unleash a couple of his trademark smashes to narrow it down to 10-12. Sen stayed in the long rallies and waited for his opponent to wilt, leading 13-11.

Sen stayed composed and his tactical play earned dividends as Lee fall into a heap of unforced errors to allow the Indian lead 17-12.

A net error from Lee was followed by a desperate return which went wide. Sen gathered two more points before grabbing seven game points when Lee erred again and the Indian sealed it in the first chance to take a 1-0 lead in the match.

After the change of sides, Lee stepped up his pace and quickly took a 9-2 lead. He mixed his shots well, varied the pace and also showed great reflex to outshine a fighting Sen.

The Indian smashed one out to allow Lee grab a huge 11-3 advantage at the break. The Malaysian was on fire after the breather as he unleashed a series of winners to zoom to 16-5.

Sen clawed his way back to 10-16 with five straight points before Lee prevailed in a long rally and then sent one across the forehand of the Indian. A smash earned Lee nine game points and closed it after another exciting rally to roar back into the contest.

The duo continued to play at a frantic pace in the decider with Sen managing a 3-1 lead early on but Lee quickly unleashed a backhand cross court return to level the score.

Lee seemed a step ahead in his pace and won a 67-shot rally next with Sen struggling at the back of his court.

A 372 km/per hour backhand smash gave another point to the Malaysian, who led 7-5 at one stage.

A calm Sen drew parity at 8-8 with Lee going long. A body return gave the Indian another point but Lee managed to grab a two-point lead at the interval.

Playing with the drift now, Sen marginally erred in his lifts which went long and Lee was quick to move to 14-10. A fighting Sen managed to narrow it down to 16-17 and then came up with a cross-court smash to soon grab two match points. Lee saved one before the Indian sealed it.

Indian women's doubles pair of Treesa Jolly and Gayatri Gopichand will take on Chinese pair of Zhang Shu Xian/Zheng Yu in the semifinals later in the day.