JOIN USJuan Martin del Potro raised the roof as he came from behind to beat Milos Raonic 5-7, 7-6 (7/1), 7-6 (7/3) and power into a Miami Open semifinal clash with American John Isner.
Roared on by a partisan crowd, del Potro rallied after losing the first set to finally wear down the Canadian in two hours and 53 minutes of relentless drama.
There was little difference between these two big hitters, but it was the Argentine who held his nerve when it counted to book a last-four encounter with Isner on Friday.
"I love to play in matches like this," a visibly weary del Potro said after his 15th straight match win.
"We both played well, the difference was perhaps that I just played better in the tie-breaks.
"I am tired now, but at least I have a day off to prepare for Friday. It's going to be important that I recover physically and mentally because that was a real battle."
Isner will, however, be a difficult nut to crack with the American recovering from an early-season slump to play some of the best tennis of his career.
His destruction of South Korean Chung Hyeon 6-1, 6-4 was impressive considering the 14th seed arrived in South Florida having won just two matches all year.
Venus toppled
Qualifier Danielle Collins sent Venus Williams crashing out 6-2, 6-3 to reach the semifinals in the women's event.
It was an amazing effort from the 24-year-old in just her second season as a professional and her debut appearance at Key Biscayne.
This was the first time in two attempts Collins has beaten a top 10 player, and even the crestfallen world number eight Williams would find it impossible to admit Collins didn't deserve to seal a meeting with French Open champion Jelena Ostapenko on Thursday for a place in Saturday's final.
"I don't think it was my best night of tennis, but there wasn't a shot she couldn't make," Williams said. "She played very well and aggressively, and she went for every shot and it landed."
Collins was simply delighted with the win over a player she idolised.
"The first time I saw Venus in the locker room I nearly cried," Collins said. "She has been my favourite player so I am finding it difficult to wrap my head around this.
"All young American girls look up to Serena and Venus. I can relate to them and their upbringing. I didn't come from a wealthy family so didn't start playing at the country club as a kid.
"Playing on public courts helped give me a different perspective. It makes you grow up and even at a young age I was pretty mature."
Ostapenko defeated fourth seed Elina Svitolina, running out a deserved 7-6 (7/3) 7-6 (7/5) winner.