Hidden behind the artistic beauty of Roger Federer's tennis lurks the primal instinct of a cold-hearted killer and on Thursday Andy Murray was the unwitting victim as he was hammered 6-0, 6-1 in his own backyard.
Already assured of a place in the semifinals of the ATP World Tour Finals after Kei Nishikori's three-set win in Group B earlier in the day, Federer only required a set against Murray to top the standings.
He managed that objective in 24 spellbinding minutes, allowing former Wimbledon champion Murray only eight points in the opening set, then went in pursuit of a rare "double bagel" -- the nickname for a tennis whitewash.
At 6-0, 5-0 and 30-0 ahead on Murray's serve the O2 crowd, many of whom were in the Federer camp, held its breath.
Swiss maestro Federer then missed a relatively easy volley and Murray somehow clawed his way to a game -- avoiding the fate that befell Argentina's Gaston Gaudio in 2005 when Federer recorded the only 6-0, 6-0 win in Tour Finals history.
Federer ended Murray's torment a game later and will now go in search of a seventh season-ending title to cap a remarkable comeback year for the 33-year-old after a disappointing 2013 when his powers appeared on the wane.
Tournament debutant Nishikori deservedly joins Federer in the last four as Group B runner-up after beating alternate David Ferrer 4-6, 6-4, 6-1 in the day's first singles.
Ferrer was a late replacement for Milos Raonic after the Canadian withdrew on Thursday morning with a leg injury and almost inevitably the dogged Spaniard ensured the first three-set match of a round-robin phase littered with easy wins.
Who they play on Saturday will be decided on Friday when world number one Novak Djokovic looks to wrap up top spot in Group A against Tomas Berdych and Marin Cilic faces Stanislas Wawrinka. Victory for Djokovic would also guarantee he finishes the year on top of the rankings.
For Murray, his year ended in crushing fashion. "Everything he tried tonight came off," Murray, still sweating, said minutes after coming off court. "It's not a nice way to finish the year."
Strangely, Murray was 0-30 ahead on Federer's opening service game and was then involved in a sensational baseline rally that ended when he netted a forehand.
From that moment on Federer took control as only he can.
Striking nonchalant winners from the baseline, teasing his quarry with drop shots and lobs and flashing away volleys, the points raced by in a blur with Murray's head spinning.
The only sympathy seven-time Wimbledon champion Federer appeared to show Murray was afterwards, as he spoke on court.
"Clearly I'm very happy to play a good match today," he said. "I knew I was qualified so maybe I went in more relaxed.
"It's not the way I thought it was going to go but there's always next year for Andy, hopefully he'll have a good season."
While Federer continues to defy the passing years, Nishikori showed again that he will be part of the next generation challenging for Grand Slam silverware.
The 24-year-old only found out that he was playing Ferrer rather than the big-serving Raonic shortly before the match, but after re-adjusting to the very different challenge the Spaniard presents, the US Open runner-up played beautifully.
"The final set [was] almost perfect," said Nishikori, who leads the ATP Tour in winning decisive sets with a 21-2 record.
Ferrer, beaten in nearly three hours by Nishikori in the quarterfinals of the Paris Masters, a result that scuppered his hopes of qualifying for the year-ender by right, hit back from a break down to snatch a high-quality opening set.
From then on, however, Nishikori showed why he has become a trailblazer for Asian tennis, unleashing his full repertoire to run Ferrer into the ground.
After converting his first set point in the second set with a backhand winner, Nishikori raced ahead in the decider against a tiring opponent, who returns home around $85,000 richer for his brief appearance in London.
