He accompanied the celebratory gesture with a skip in his step and then hit the accelerator, holding every service game to beat Dudi Sela 6-3, 6-4.
Thus began Nadal's latest bid to win Key Biscayne.
''A lot of big motivation,'' he said.
He's playing the tournament for the 13th time and has never won it, although he was the runner-up in 2005, 2008, 2010 and 2014. At 0 for 12, it's Nadal's longest drought at any event, and perhaps the most glaring gap in the 14-time Grand Slam champion's resume.
Does it bug him? He won't admit to any frustration, but let slip that he still remembers the exact score when he was two points from the title in the third set versus Novak Djokovic.
That was six years ago.
''Against Novak - 6-5, 15-30,'' Nadal said. ''It didn't happen.''
The Spaniard has always enjoyed the atmosphere in Miami, where Latin fans give him enthusiastic support, and he likes the tournament's hard courts. He's simply overdue.
''I'm trying my best every year,'' Nadal told the stadium crowd after dispatching Sela. ''I've been very close four times. I will try to give myself another chance.''
No. 11-seeded Venus Williams, whose third and most recent Key Biscayne title came in 2001, won her opening match against Beatriz Haddad Maia, 6-4, 6-3. No. 1 Angelique Kerber played until nearly 1 a.m. to beat Duan Ying-Ying 7-6 (3), 6-2.
Nadal is 15-4 this year and pleased with his play. He lost to Roger Federer in the Australian Open final, and again in the fourth round at Indian Wells last week.
Against Sela, Nadal served well, erased the only two break points he faced and overcame the occasional errant groundstroke on a windy afternoon.
''It was very difficult to find the right feelings,'' Nadal said. ''These kind of days, what you have to do is try to win. That's what I did, and I'm happy with that.''
Making Nadal's title bid easier will be the absence of six-time champion Djokovic and two-time champion Andy Murray, both out with elbow injuries.
But No. 3-seeded Milos Raonic is back. He won in his first match since Feb. 25, beating Viktor Troicki 6-3, 7-5. Raonic had been sidelined by a right leg injury.
''I've prepared the best I can for this tournament,'' Raonic said. ''I'm not necessarily in the best position right now, but fortunately it's a long tournament. Doesn't mean things can't change and I can't get better throughout this event.''
No. 2 Kei Nishikori beat Kevin Anderson 6-4, 6-3. No. 7 Marin Cilic lost to Jeremy Chardy 6-4, 2-6, 6-3. American Jack Sock, seeded 13th, advanced when Yoshihito Nishioka retired with an injury leading 4-2 in the first set.
In women's play, Elena Vesnina made a quick exit only five days after winning the biggest title of her career. Seeded 13th, Vesnina lost her opening match to wild card Ajla Tomljanovic 3-6, 6-4, 7-5.
Vesnina beat Svetlana Kuznetsova in the Indian Wells final.
In a match that took two days because of rain, No. 6 Garbine Muguruza rallied past Christina McHale 0-6, 7-6 (6), 6-4. No. 3 Simona Halep beat Naomi Osaka 6-4, 2-6, 6-3. American qualifier Taylor Townsend eliminated No. 25 Robert Vinci 6-3, 6-2.