This was the 30 year-old Scot close to his smartest and toughest, and he was left awaiting the victor between giant American John Isner and 21 year-old Russian Karen Khachanov, reckoned to be one of the game's best prospects.
The match had been delayed because of rain.
epa06003551 Andy Murray of Britain in action against Martin Klizan of Slovakia during their men?s single 2nd round match during the French Open tennis tournament at Roland Garros in Paris, France, 01 June 2017.
His expectations on arriving in Paris were rather different to normal after a poor run of form on the clay, but Murray looked much more like his usual self in a straight-sets win over Juan Martin del Potro on Saturday.
The unseeded Cornet was a surprisingly easy victor over No. 9 Agnieszka Radwanska of Poland, 6-2, 6-1, while No. 28 Garcia edged Hsieh Su-wei of Taiwan 6-4, 4-6, 9-7.
Working things out tactically and making adjustments during matches gives me confidence, so that's been a real positive for me over the last couple of matches.
Khachanov, born in Moscow but based in Barcelona, is through to the last 16 at a slam for the first time.
"If he hits the ball as big as he did today, I think he can keep it close [against Murray]", said Isner after his 7-6, 6-3, 6-7, 7-6 defeat.
"If I say something, you guys ask me what I was saying; if I say nothing, you ask me why I don't say anything".
Wawrinka broke him in the next game and then served out the match.
After 4 hours, 17 minutes of hard slog, the 20th-seeded Carreno Busta will have used up valuable energy for his quarterfinal against nine-time champion Rafael Nadal.
But you then have another 15 to 20 seconds to either calm yourself down and think about the next one, or spend that time thinking about what just happened - "why did I just get broken serving for the set?"
It was the precursor to what turned out to be a 7-6 7-5 6-0 victory in this French Open third round - and it could be a massive one in the context of the season. Those sets were very decisive.
Garcia, seeded 28, made the 4th round of a Slam for the first time with a 6-4, 4-6, 9-7 win over Taiwan's world number 109 Hsieh Su-Wei. It was a rematch of the 2016 Rio Olympics gold-medal final won by Murray.
Former US Open champion Marin Cilic continued his smooth progress seeing off Feliciano Lopez, who was limited by a neck injury, 6-1, 6-3, 6-3.
The tiebreak was a mini-match in itself, with Murray opening up a 6-4 lead, missing both set points then facing another after Del Potro pulled off a miracle forehand victor off a Murray pass.
2015 champion and third seed Wawrinka faces the last Frenchman in the draw with their series level at 2-2.
Cornet punched the air with delight after sealing victory on her next chance with a clipped backhand at the net.