The Frenchwoman will make her top-10 debut when the new rankings come out on Monday.
The Spaniard remains unbeaten since he became world number one in August and put in a ruthless display on his way to his 75th career title.
Troubled Australian tennis star Nick Kyrgios says he has finally found a goal in life and will build a facility for disadvantaged kids after being struck by the death of a young boy from cancer.
The 31-year-old saved two match points in his nervy opener against Frenchman Lucas Pouille, but was never really in trouble as Kyrgios's final hopes evaporated in acrimony.
Kyrgios offered Nadal eight break points in the first set with Nadal taking two service breaks.
Unseeded French player Garcia continued her superb run of form of late as she comfortably overcame Halep, the Romanian who will be confirmed as the world number one for the first time tomorrow, in straight sets at the Olympic Green Tennis Center.
Nadal has one of the best defence in tennis right now, but he needs to be wary of Kyrgios' big-serving ability.
And from 2-2 in the opening set, Kyrgios fell apart with Nadal winning four games in a row - made easier when Mohamed Lahyani handed a point penalty to Kyrgios during the change of ends at 2-5.
"She played incredible tennis", Halep said of Garcia. The wildcard entries beat the second seeds 6-4 7-6 (7-1) for their first ATP World Tour team title. Garcia fell to her knees in celebration.
"It was such an unbelievable two weeks", Garcia said.
Relishing Sunday's clash with Nadal, the Spanish 16-time Grand Slam champion, Kyrgios added: "He's one of the greatest players of all time and we've played a couple of times - he's beaten me and I've beaten him (this year)".
The last time Kyrgios played a No. 1 it was also against Nadal. He won his first in his Beijing debut in 2005.
Nadal leads Kyrgios 3-2 in career meetings, and 2-1 this season.