* Vettel leads the way in free practice
* Grosjean fastest in hot afternoon session (Adds quotes)
By Alan Baldwin
ABU DHABI, Nov 1 (Reuters) - Newly-crowned quadruple world champion Sebastian Vettel showed no signs of easing off as he led a familiar Red Bull one-two in free practice for the floodlit Abu Dhabi Formula One Grand Prix on Friday.
The 26-year-old German, who secured his fourth successive title in India last weekend and will be chasing a seventh race win in a row on Sunday, scorched around the Yas Marina circuit with a best time of one minute 41.335 seconds in the evening session.
Australian team mate Mark Webber was 0.155 slower.
"It's difficult to say today how we compare to the others, we know the Lotus is quick here, but we also had decent pace today," said Vettel of his day's work.
"It's not always so easy at this circuit with the conditions changing throughout the day; we start in the sun and finish at night and the track temperature changes during that time. But, no big issues, so I'm pretty happy."
Lotus's Romain Grosjean, whose team mate Kimi Raikkonen won last year's race, was fastest in the searing afternoon heat in 1:44.241 but had a front brake failure under the floodlights.
Force India's Paul Di Resta and McLaren's Jenson Button both suffered punctures.
Lewis Hamilton, winner in 2011 and twice on pole at the circuit, was second quickest for Mercedes in the opening session, just 0.192 slower than Grosjean, and third in the evening.
Raikkonen, who revealed he had considered not turning up in Abu Dhabi over unpaid wages and other issues with the team, was sixth and fourth fastest respectively.
Grosjean has beaten Raikkonen in the last two races and finished on the podium in the last three.
A seventh successive win would allow Vettel, the sport's youngest quadruple champion, to equal fellow-German Michael Schumacher's 2004 streak which stands as the longest winning run of the modern era.
The record of nine was set by Italian Alberto Ascari over the 1952 and 1953 seasons.
Red Bull have already clinched their fourth successive constructors' title and the focus is now on whether anyone can stop Vettel winning the last three races of the year and the runner-up slot in the constructors' championship.
Webber was fourth quickest before the sun set and the floodlights came on, with Nico Rosberg fifth for Mercedes in both sessions.
"We didn't learn a great deal during the first practice session today as it was so hot and we won't have those conditions in qualifying or the race," said Rosberg.
"It should be an interesting race from a strategy perspective as the tyres seem to be right on the limit of one or two stops. Our aim is to be the best of the rest again which I'm quite confident we can achieve."
Mercedes are second overall and four points ahead of Ferrari, with Lotus a further 24 adrift.
Ferrari's Fernando Alonso, who had been the only man mathematically capable of making Vettel wait for the title in India, was 12th and eighth with Brazilian team mate Felipe Massa 17th and 10th.
"Compared to other Fridays, today we were a bit less competitive than usual and now we need to work out if that is down to the fact that the track characteristics do not suit our car, or if it's a question of set-up," said Alonso.
"Unfortunately, in performance terms, we are behind our rivals for second place in the constructors' classification." (Editing by Ed Osmond and Alison Wildey)