Middle of the first set. Same swing speed as 1st serve.
After having won the first 2 sets 6-1, 6-1, and leading 5-0, 40-0 before losing 6-7, and 6-7 the 4th set and now down match point in the 5th set after blowing a 5-0 lead again.
2nd serve swing speed = 1%. Tap it in serve