SHANGHAI, October 26, 2013 (AFP) - Guthrie suffered bogeys at the 16th and 18th to drop him back to the field with a level-par round of 72. Meanwhile the Spaniard shot a fine five-under round of 67.
"I'm happy, confident and enjoying the tournament so far," said Carbrera-Bello after his round. "Hopefully tomorrow I can keep those feelings and take them out on the golf course with me and play my best."
But the huge crowds had come to see McIlroy, and he had looked all set to get into contention as he began the back nine with four birdies in a row to get to four-under par.
The former world number one, who has struggled with his game all year, showed some of his old magic as his birdie blitz propelled him up the leaderboard.
With a birdie opportunity at the par-five 15th to come, it looked odds-on that McIlroy would be within touching distance of the leaders going into Sunday's final round of the $7 million event.
But further birdies would not materialise as his touch on the greens deserted him, and three putts after splashing out to 15 feet at the last put him back to two-under for the tournament and provoked his angry response.
The 24-year-old banged his putter angrily on the steps leading to the scorers' hut at Lake Malaren in Shanghai after a disastrous double-bogey six at the fearsome finishing hole all but blew away his title hopes.
McIlroy had been in jovial mood all week after finishing second in Korea last Sunday, but refused to talk to reporters as he stomped back to the clubhouse.
Playing partner Gregory Bourdy of France did manage to get up and down at the last, however, to complete a fine bogey-free round of 67 to lie in fourth place at six-under par.
"It was very important to get that par and keep the momentum going," said the Frenchman, who won the Wales Open this year and starred for the European team in the Seve Trophy last month, winning five points out of five.
"It's a tough hole, 18, and you can see with what happened to Rory that it's very easy to drop back quickly," he told AFP.
In third place is another Spaniard, Fernando Gonzalez-Castano, on seven-under par. He was one of the few players to tame the fearsome 471-yard 18th hole as he made a birdie to return a card of 67.
"I hit a very good drive and I knew the pin was in a kind of hollow so if you can put the ball in there you're going to leave yourself a makeable birdie putt," he said. "And that's exactly what I did."
The wind, though lighter than the first two days, was still a big factor on the tough Jack Nicklaus-designed 7,607-yard Lake Malaren layout. The difference was clearly seen in the scores compared to last year when conditions were calm.
Then Peter Hanson of Sweden won the BMW Masters with a 21-under par total. It seems that 10-under could be good enough this year with the wind forecast to blow hard again on Sunday.
Earlier in the day, a distraught Simon Dyson of England, who had been in a six-way tie for second after Friday's play, left for the airport after being disqualified before he could start his third round on Saturday morning.
Several television viewers had noticed him illegally tap down something on the eighth green on Friday and emailed the European Tour.
After viewing footage, he was deemed to have touched the line of his putt in contravention of the rules. The offence carries a two-shot penalty, but as Dyson had already signed for a round of 70 and not 72, it meant the end of his tournament.
Leading scores on Saturday after three rounds of the European Tour's $7 million BMW Masters at Lake Malaren Golf Club, Shanghai (par 72):
208 - Rafael Cabrera-Bello (ESP) 73-68-67, Luke Guthrie (USA) 65-71-72.
209 - Gonzalo Fernandez-Castano (ESP) 71-71-67.
210 - Gregory Bourdy (FRA) 70-73-67.
211 - Paul Casey (ENG) 70-70-71, Craig Lee (SCO) 70-70-71, Scott Jamieson (SCO) 72-68-71.
212 - Pablo Larrazabal (ESP) 70-73-69, Thongchai Jaidee (THA) 70-70-72.
213 - Marcus Fraser (AUS) 73-70-70, Lee Westwood (ENG) 72-71-70, Bernd Wiesberger (AUT) 75-69-69, Peter Uihlein (USA) 69-75-69.
214 - Ricardo Gonzalez (ARG) 73-67-74, Maximilian Kieffer (GER) 72-72-70, Rory McIlroy (NIR) 71-72-71, Padraig Harrington (IRL) 72-72-70, Thomas Bjorn (DEN) 73-72-69, Soren Kjeldsen (DEN) 76-71-67, Francesco Molinari (ITA) 72-71-71
215 - Ian Poulter (ENG) 74-69-72.
216 - David Horsey (ENG) 72-72-72, Danny Willett (ENG) 74-72-70, Martin Kaymer (GER) 75-71-70.