PV Sindhu and Nozomi Okuhara did not follow the script like their previous few matches against each other.
Saina let go a 14-10 lead in the opening game and a 6-4 advantage in the second to go down 21-16, 21-13 to Olympic champion Carolina Marin of Spain. At the end of the break, the Indian shuttler was leading the game 11-9. Okuhara now leads the head-to-head record against Sindhu, 5-4.
The second game was a different scene altogether.
The Japanese girl, who was supported by a loud and partisan crowd, took just 47 minutes to beat the fourth seeded PVSindhu 21-18, 21-8 at the Tokyo Metropolitan Gymnasium.
Prannoy will now take on second-seed Shi Yuqi of Hong Kong for a place in the semi-finals.
The US Open champion HS Prannoy was equally impressive and staved off a late challenge from the World No. 26 Hsu Jen Hao for a 21-16, 23-21 win in exactly 1 hour.
The rock-steady Prannoy experienced some anxious moments in the second game before getting the measure of the Taiwanese player. World No 8 Srikanth, who clinched back-to-back titles in Indonesia and Australia this year, demolished Hong Kong's Hu Yun 21-12 21-11 within half an hour to make it to the final eight.
So tough has the competition been between Sindhu and Nozomi in the past, that this was only the second time in nine matches that the encounter did not proceed to the deciding third game.
World number 2 Yuqi, who had reached the finals of All England Championship early this year, staved off a challenge from Syed Modi International victor Sameer Verma 10-21, 21-17, 21-15 in an hour and 5 minutes. But then, that problem will also affect the hard-hitting Axelsen; and the match could come down to a single factor - who controls the net and gets his rival to lift the shuttle to the midcourt, for the administration of the coup-de-grace.