The London Olympic bronze medallist hardly had to break sweat in the opening game though.
The match swung one way and then another for an hour and twenty minutes before a smash finally gave Long the 21-15 21-23 21-19 win.
World No.2 improves record over Nehwal to 8-1 with QF win; Kashyap loses later to end Indian challenge.
He won 18-21, 23-21, 21-13, even as his opponent Dionysius Rumbaka of Indonesia appeared to pull a thigh muscle in the third game.
Saina will have to overturn 1-7 personal record against Yihan to make semis.
Kashyap beats World No. 7 Zhengming Wang but Sindhu bows out to All-England champion in first round.
Sindhu, world number 9, has a more difficult task as she faces second seed and reigning All England champion Shixian Wang in the opening round.
At 182 cm, Sun Yu (19) is China’s and their women’s coach, Chen Jin’s, big hope for the future in badminton.
Kashyap’s next opponent is world number 22 Tien but the Indian will take heart from the fact that he had beaten him in the Macau Open in 2011.
Meanwhile, Saina opened her campaign with a straight game win over qualifier Chisato Hoshi of Japan.
But it was curtains for Kidambi Srikanth in the men’s singles, while Saili Rane failed to cross the opening hurdle in women’s singles.
Lee Chong Wei brought his experience into the game, wearying out his opponent’s patience.
Saina’s loss in the last-eight stage of All England Championship ends Indian hopes in the event.
Seventh seed Saina defeated the American qualifier 24-22, 18-21, 21-19 in an hour in the second round contest.
Saina was the only bright spot on a dismal day for Indian badminton as she notched up an easy 21-15 21-6 win.
The All England has remained an elusive mirage for India’s most successful badminton player - Saina Nehwal.
At 34, Bhat became the first Indian since P Gopichand to win a Grand Prix Gold-level title in Europe.
He won mixed doubles gold at the 2008 Games in Beijing and a bronze medal in the men's doubles in London.
Top seed beats Sindhu to win Syed Modi title, her first in more than a year.
Saina will face second seed PV Sindhu in the summit clash.
In the women’s doubles event, Muenwong and Ostermeyer beat duo of Gutta and Ponnappa 21-14, 21-11 in the quarterfinals.
An out of sorts Kashyap said he committed many unforced errors that proved costly for him.
Saina continued her march towards the season's first title with a 21-5 21-10 victory over Russia's Perminova.
In a mixed doubles match, the Malaysian pair of Khalid and Soong defeated the Indian pair of Sanyal and Jwala.
Saina went down fighting 21-16 10-21 19-21 to a lower-ranked Yao Xue of China.