The set figures were written to 6–1, 3–6, 6–3, 6–4 on the center court and the Spaniard is now ready for the fourth round.
Despite a weaker performance in the second set, Alcaraz quickly found his way back, among other things by only losing four points in his own serve in the third set.
Struff struggled hard, but Alcaraz broke to 5–4 in the fourth set and then safely served home the victory.
The 22-year-old Alcaraz thus extended his winning streak to 21 consecutive matches in total and 17 on the grass in London, where he has already won the tournament two times in a row.
