The Mexican Ortiz also earned his spot at the major in Portrush, Northern Ireland, in July, after holding off the American for a three-shot victory at the Asian Tour event in the SAR.
Jason Kokrak also qualified as he finished third at Macau Golf and Country Club, three shots further back.
The American was one shot ahead of the 2017 Masters champion and another LIV player in Sergio Garcia.
The Spaniard missed a three-footer for birdie on the last which would have seen him tie with Kokrak and secure a place at the British Open through countback based on his higher world rankings.
The Macau tournament was added this year to the Open Qualifying Series for the first time, with the top three players who are not already exempt earning a berth at the British Open.
LIV players do not earn world-ranking points, severely restricting their chances of qualifying for golf’s four major tournaments.
Ortiz carded a final-round six-under-par 64 to triumph with a total 22-under.
Reed, the 2018 Masters champion, had shared the lead with Ortiz heading into the final round but had to settle for a runner-up finish after carding a 67.
Reed’s best performance at the British Open was 10th in 2019. (AFP)
