Alcaraz, 19, had a tough time breaking through against his determined Dutch foe, who had won their only prior hard court meeting.

He didn’t face a break point in the first set, but nor could he convert either of his two.

A strong start in the tiebreaker, which saw him take a 5-2 lead with a service winner, proved the difference, Alcaraz locking up the set with a forehand winner on his second set point.

He rolled from there, breaking Griekspoor in the second game on the way to a 3-0 lead in the second set.

Griekspoor saved a match point in the penultimate game, but after falling behind 0-30 in a nervy final game Alcaraz won four straight points, finishing it off when Griekspoor sent a forehand wide.

Once again Alcaraz showed no sign of the right hamstring strain he suffered on the way to the final last month in Rio de Janeiro – a week after he’d won the ATP title in Buenos Aires.

Last year’s US Open winner had missed the Australian Open with a similar injury.