Despite establishing a 5-2 advantage during the second set, Jack Draper suffered a straight-sets loss in his opening-round match at the Cincinnati Open.
In what was his initial appearance on court since an emotional injury comeback last week, the British player seemed poised to push his match against Spanish opponent Martin Landaluce into a third set.
However, the former world number four squandered six opportunities to take the set, enabling the 20-year-old Spaniard to secure five consecutive games and wrap up a 6-3 7-5 win.
The 24-year-old Draper committed 47 unforced errors alongside 12 double faults throughout the match against his opponent, who is ranked 64th globally.
This encounter marked only his second competitive outing since June, following a recent defeat to Terence Atmane at the Canadian Open.
An ongoing arm issue had previously kept Draper off the tour, dragging his global ranking down from a peak of fourth to a low of 160th over the course of a year.
Following a shoulder injury sustained during the US Open in August, Draper has dealt with bone bruising, forcing him to withdraw from planned return appearances at Wimbledon and the Washington Open earlier this summer.
Although he showed no obvious physical distress while playing Landaluce, his energy levels dropped in the second set, and his self-belief appeared to evaporate after the Spaniard leveled the score at 5-5.
To address his persistent physical struggles, Draper has lately been working with biomechanics specialist Carlos Cano, a 61-year-old Mexican coach who previously guided Arthur Fery to the top of the British rankings.
