Jack Draper came up short on making it a clean sweep of British winners overnight after missing out to Thanasi Kokkinakkis in three sets.
Draper served for the match at the Los Cabos Open in the second set but was broken, narrowly lost the subsequent tiebreak and was eventually outplayed 4-6, 7-6, 6-4 by his Australian opponent.
The Briton had looked the better of the two players for much of the opening two sets before Kokkinakis began to swing more freely at the ball, and was the deserved winner.
Draper’s loss denied an all-British second-round encounter against Dan Evans, who impressively knocked out No2 seed Roman Safiullin 6-2, 6-4.
The British No2 struggled with his serve but was the far more clinical when it came to converting breaking points, taking five from eight in a match.
Elsewhere at the Rio Open, Cameron Norrie had an easy victory 6-3, 6-w over Hugo Dellien, taking just an hour and 20 minutes to ease into the second round.
It was a restorative result having been knocked out early in Argentina last week, a result which saw him tumble out of the world’s top 20.
After beating Dellien, Norrie said: “I served much better than last week and I was a bit more patient and knew I had to play point for point and really make the rallies a bit longer. I think I learned from last week with that, and just happy to be back in Brazil.”
Norrie has points to defend in Rio having won the title last year by beating Carlos Alcaraz.
Andy Murray is in action later on Tuesday as he bids to make up for his difficult start to 2024 at the Qatar Open
