London - South Africa's Kevin Anderson lost to Frenchman Gilles Simon in the second round of the Queen's Club grass court event on Thursday.
The French journeyman won 6-1, 4-6, 6-4 to advance to the third round.
Anderson, seeded second at the event, won his first round match 4-6, 7-6 (7/5), 6-4 against Britain's Cameron Norrie on Monday.
Anderson, the world No 8, returned to court for the first time since March after missing the clay court season due to a lingering elbow injury.
He will now set his sights on Wimbledon, where he reached the final last year before losing to Serbia's Novak Djokovic.