World No.10 Sindhu registered a 21-19, 21-10 triumph in the semi-finals over world No.6 Okuhara to become the first Indian shuttler to enter the final of the Olympics.
With this win, double World Championship bronze medallist Sindhu improved her head-to-head record against reigning All England Open champion Okuhara to 2-3.
In the final, she will face two-time reigning world champion Carolina Marin of Spain, who beat defending champion Li Xuerui of China 21-14, 21-16.
Irrespective of the colour of the medal in the final on Friday, it will be India's second medal in the Rio Games after wrestler Sakshi Malik bagged a bronze medal in the women's 58kg category.
For Sindhu, who was on a giant-killing spree after dismissing two higher-ranked opponents -- Chinese Taipei's Tai Tzu Ying and World No. 2 Wang Yihan of China in the pre-quarter-final and the quarter-final respectively -- Thursday's win was also an extension of her good form.
Sindhu's height and long reach gave her a lot of advantage against the pint-sized Okuhara, who also had her right thigh strapped.
Especially, Sindhu's sharp cross-court game and half smash helped her get off to a fine start.
In the first game between the two 21-year-olds, Sindhu started the match on a positive note, taking a 4-1 lead before the Japanese reduced it to 3-4. But Sindhu took two straight points to hold a 5-3 lead before Okuhara got a point to sit at 4-5. But Sindhu upped the ante and took a 8-4 lead before Okuhara bagged two points as Sindhu hit wide.
Sindhu reached the mid-game interval with a 11-6 lead and after a two-minute break, Okuhara's delectable drop shots helped her bounce back. She was trailing 10-12 when Sindhu forced her to hit the net and take a 14-10 advantage.
Later, Sindhu took a 15-12 lead that became 17-14 but Okuhara's net game helped her almost reduce the deficit. She kept coming back at Sindhu, forcing the Indian to make some unforced errors -- hitting wide.
But Sindhu remained always in the lead, albeit a slender one-point advantage, before winning the game 21-19.
In the second game, Sindhu again began convincingly taking a 3-0 lead before Okuhara took five straight points to sit at a 5-3 lead.
Afterwards it was a neck-and-neck contest. Sindhu rattled Okuhara with two straight points as the Japanese hit wide and failed to return a fierce smash from the Indian.
Okuhara again held the lead at 7-5 and at the mid-game interval Sindhu led 11-10.
After the break, Sindhu turned more aggressive and played a fearless game to stun the Japanese who looked short of ideas.
Sindhu kept earning points, hitting one smash after another to enjoy a comfortable ride. As many as 10 points on the trot catapulted her to the final with a 21-10 win in the second game.
Afterwards, what followed was a screaming celebration from Sindhu and her camp.
