With the top spot in Group Ilie Nastase confirmed, Rafael Nadal remained unbeaten in his Barclays ATP World Tour Finals round robin campaign, extending his perfect mark to 3-0 on Friday. Countryman David Ferrer turned in a valiant effort after rallying from two breaks down in the first set, but Nadal responded in kind, wrapping up the thrilling victory 6-7(2), 6-3, 6-4.

Following a rocky start to 2015, the World No. 5 is gaining significant momentum at the season finale in London. A 17-4 post-US Open mark has included five Top 10 wins and now three straight this week at The O2. He enters an Open Era record 46th clash against Novak Djokovic in Saturday's semi-finals after surviving a gritty two-hour and 37-minute battle against Ferrer. Tested often, he refused to back down, even with a semi-final berth already assured. 

Nadal, who notched his 60th win of the season on Wednesday, secured the immediate advantage, breaking Ferrer to 15 in the first game of the match. Stepping inside the baseline, a rifled backhand winner down-the-line and Ferrer forehand error put him ahead 1-0. Nadal claimed 10 of the first 11 points as he raced to a 3-0 lead behind a second break. But Ferrer would go on a run of his own, taking 12 of 14 points to snatch both breaks back and draw level at 3-3. They would again exchange breaks in the 11th and 12th games, as Ferrer broke Nadal serving for the set at 6-5 - saving a set point - following a seven-minute game. In the tie-break, a wayward lob and double fault from Nadal would give Ferrer a pair of early mini-breaks and he would emerge with the opener after exactly one hour.

Ferrer used his forehand to attack Nadal's own forehand in the Ad court, with 90 per cent of his winners in the first set coming from this side. Ferrer would win a 14-minute opening game to the second set. He would also battle to hold for 3-3 after saving a break point, despite Nadal winning the point of the match - a grueling 26-shot rally that he punctuated with a backhand cross-court winner. Minimising his unforced errors, Nadal would grab his fourth break of the match two games later and drew level at a set apiece.

Fans at The O2 were rewarded with a pulsating three-set battle, as Ferrer saved five break points in the opening game of the third to hold. A sublime corner-to-corner lob for Ferrer fell smack on the line and brought the London faithful to their feet during the near-14 minute game. They would remain on serve until the eighth game, when a Nadal forehand error moved his compatriot to two points from serving for the match at 4-3 0/30. Nadal would do well to hold, turning defence into offence in a flash with a pulsating shot-making display. A flick forehand winner down-the-line at 15/40 in the next game - his sixth break chance of the set - would yield the decisive break for 5-4. He would finish with 32 winners and five breaks from 12 opportunities.

Nadal now leads the FedEx ATP Head2Head series 24-6, having claimed their previous meeting this year on the clay of the Monte-Carlo Rolex Masters. They had split their two encounters at the season finale, with Ferrer capturing the encounter in Shanghai in 2007 and Nadal winning in 2013 at The O2. Ferrer was looking to cap his 2015 season on a high note, playing in his last match following an 0-2 start. He concluded the year with a 55-16 overall record, with titles in Doha, Rio de Janeiro, Acapulco, Kuala Lumpur and Vienna.

Nadal had confirmed his place opposite Novak Djokovic - runner-up in Group Stan Smith - in Saturday's semi-finals after defeating Andy Murray and Stan Wawrinka earlier in the week. He qualified for the last four at the season finale for a fifth time in seven appearances.