Daniil Medvedev suffered consecutive opening game losses as he was dumped out of the Cincinnati Open by Jiri Lehecka in straight sets.
Medvedev, who was beaten by Alejandro Davidovich Fokina in Montreal last week, endured another early exit, losing 7-6 (7-2) 6-4 in just under two hours against the Czech.
“It’s amazing to be back, to be honest. To get a win against such a talented player as Daniil surely is, is just such a bonus for me," Lehecka said on being back in his first tournament in three months after injury.
Lehecka squandered four game points in the opener, with Medvedev also missing an opportunity for an early break, but the Czech was able to hold his opening serve.
The pair traded blows for the remainder, but the world number five struggled in the tiebreak, losing three games in a row to hand Lehecka the advantage.
And the decisive moment came in the seventh game of the second, as Lehecka broke Medvedev's serve, edging closer to a memorable triumph.
The Czech missed four match points in the final two games, but was not to be denied a fifth time, ending the encounter with a fierce serve to set up a meeting with Frances Tiafoe in the next round.
Data Debrief: Lehecka continues winning return in Cincinnati
Since 1990, Lehecka is now the fourth player ranked outside the ATP's top 30 to claim top five wins at three ATP Masters 1000 events in a season after Gaston Gaudio (2001), Hicham Arazi (2001) and Tommy Paul (2022).
Excluding the ATP Tour Finals, Medvedev has been defeated in three consecutive ATP matches on hard court for the first time since October in 2017.