Another rain delay sent the players off court and shortly afterwards play was suspended for the day.
Four years after a 20-year-old Garbine Muguruza let her mind run off with a win before her body had accomplished it, and lost a quarterfinal to Maria Sharapova by 1-6, 7-5, 6-1, Muguruza brought a 24-year-old mind to another quarter-final and blasted Sharapova to smithereens by 6-2, 6-1, in 70 deeply serious minutes. It was the second interruption of the match; Schwartzman, a 5ft 7in bundle of energy and snappy ground strokes, was a break up in the second set when the skies first opened. In a match that had several tie-breaks written all over it, the pair were duking it out in a ... tie-break, with the score locked at 5-5 when they were forced off court.
He went on to break Nadal two more times in the second set before the match had to be stopped due to rain.
Nadal made 14 unforced errors and struck just four winners in a poor first set, before having both of his wrists strapped by the trainer.More news: Dynasty's doorstep: Warriors take 3-0 lead in Finals
That proved costly as Nadal broke and then repeated the trick to move into a 5-3, 30-15 lead.
However, when the players came back on after a delay of nearly an hour Nadal immediately broke back to level the second set.
Two-time runner-up Halep came back from a set down for the second time in the tournament to see off 12th seed Kerber, who was bidding to become the first German woman in the last-four since Steffi Graf in 1999.