In tough circumstances created by a brisk wind within the Californian desert, Raducanu regarded 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 come back out on high of the usually 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 appeared to be aggressive.
5 of these video games led to Raducanu dropping function she trailed by a set and a break to the 52nd-ranked Uchijima.
The Briton lower a subdued determine after she couldn’t convert any of three probabilities 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 yr.
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 yr, whereas he has additionally labored with top-10 gamers Dominika Cibulkova, Daria Kasatkina and Veronika Kudermetova.
When requested which areas of her recreation she needed to work on with Platenik, Raducanu smiled and stated “every part”.
“I am going to want to enhance beginning the purpose. That is a giant a part of tennis. I can do this rather a lot higher,” she added.
“I may enhance being extra aggressive and having a greater high quality of shot going ahead into the court docket.
“I may enhance each space of my recreation after immediately’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, gained 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.
