The 72nd ranked Japanese, who had earlier upset second seed and last year's runners-up Russian Vera Zvovareva in the second round, played a focused and aggressive game to sent the 70th ranked Indian teenager out of the tournament.
Morigami thus avenged her first round loss to Sania in this year's Wimbledon Championship. The Japanese will now meet fourth seed Daniela Hantuchova in the semifinal after the latter beat Korea's Yoon Jeong Cho 6-7, 6-4, 6-1 in another quarterfinal match.
It was a disappointing show by the Indian who had humbled 36th ranked German Anna-Lena Groenefeld in straight sets in the first round before taming another higher ranked player Kristina Brandi of Puerto Rico in her second round match.
Against Morigami, Sania was quite off-colour and a series of unforced errors marred her prospect as the Japanese slowly took control of the proceedings. Sania's serve also let her down while the Japanese looked much more aggressive and eager for a revenge.
Morigami used a variety of tactics in her straight sets victory and started off the match with a break and a hold of serve for 2-0.
Sania was soon drew parity, breaking right back to bring the set back on serve. However, the Japanese player got another break late in the set to bag it 6-4.
The second set looked like a replay of the first one with Morigami breaking the Indian before holding her serve againt and Sania responding well to make it 2-2.
Sania's serve proved a big let down in the fifth game as she could not hold it and Morigami went up a break. The Japanese then needed only to hold serve which she did with consummate ease and sailed into the last four stage of the tournament.
