In difficult situations created by a brisk wind within the Californian desert, Raducanu appeared uncomfortable all through as Uchijima tailored impressively.
The 2021 US Open champion made a number of errors to permit Uchijima, a tenacious opponent who continued to place balls again into court docket, to return out on prime of the customarily scrappy rallies.
Raducanu confronted break factors in her opening six service video games, a results of the stress created by a scarcity of accuracy as she aggressive.
5 of these video games resulted in Raducanu dropping function she trailed by a set and a break to the 52nd-ranked Uchijima.
The Briton minimize a subdued determine after she couldn’t convert any of three possibilities to interrupt again for 3-3.
After Uchijima dug deep to carry, Raducanu didn’t win one other level and trudged off court docket having misplaced for a sixth time in her 9 matches this 12 months.
Raducanu was watched from the stands by Slovakian coach Vladimir Platenik, who has linked up with the British quantity two on a trial foundation.
Platenik, 49, was teaching New Zealand qualifier Lulu Solar when she beat Raducanu at Wimbledon final 12 months, whereas he has additionally labored with top-10 gamers Dominika Cibulkova, Daria Kasatkina and Veronika Kudermetova.
When requested which areas of her sport she needed to work on with Platenik, Raducanu smiled and mentioned “the whole lot”.
“I am going to want to enhance beginning the purpose. That is an enormous a part of tennis. I can try this so much higher,” she added.
“I might enhance being extra aggressive and having a greater high quality of shot going ahead into the court docket.
“I might enhance each space of my sport after as we speak’s efficiency.”
Shortly after Raducanu’s exit, British quantity three Sonay Kartal did transfer into the second spherical, taking advantage of being given a ‘fortunate loser’ spot having been crushed in qualifying.
Kartal, 23, received 7-6 (8-6) 6-2 towards 38-year-old American qualifier Varvara Lepchenko and faces Brazilian sixteenth seed Beatriz Haddad Maia subsequent.
Within the males’s draw, Jacob Fearnley was unable to arrange an all-British conflict with Jack Draper after dropping to rising star Joao Fonseca.
