Title-chasing Hamilton returns to happy hunting ground

Lewis Hamilton returns to his happiest stomping ground this weekend when he seeks to extend his world championship lead with a record-equalling seventh triumph at the Canadian Grand Prix.
The defending four-time champion, who leads nearest rival and fellow four-time champion Sebastian Vettel by 14 points after six races, claimed his maiden Formula One win at the Circuit Gilles Villeneuve in 2007.
Since then Hamilton has added five more wins including a hat-trick of Mercedes triumphs in 2015, 2016 and 2017 to move within reach of becoming the first man to secure four straight pole positions - he converted pole in each of those years - and four consecutive wins.
Hamilton's pole success last year enabled him to equal three-time champion Ayrton Senna's record of 65 pole positions, a feat that saw him presented by the Senna family with a helmet worn by the great Brazilian.
That display of emotion confirmed Hamilton's unchallenged supremacy in Montreal, but he faces a much more difficult challenge from rivals this weekend as the leading teams take their scheduled revised second engines of the season.

Mercedes team chief Toto Wolff said: "We expect a number of teams to take their second power units, including all the Mercedes cars. We are pushing for more performance as soon as possible.
"We can see that we are in a stronger position in both championships than we were 12 months ago, but we know the battle is more fierce with ourselves, Ferrari and Red Bull in contention every weekend."
Like Mercedes, both Red Bull and Ferrari are expected to use new engines, but Red Bull technical boss Adrian Newey downplayed expectations, notably because Monaco victor Daniel Ricciardo faces grid penalties for other technical power-unit changes.
Newey suggested that Renault would gain only around one-tenth of a second per lap on a power-hungry track that suits Mercedes, but Wolff warned "past performances are no guarantee of success this year.
"We need to make sure we get the most from all the tyre compounds, including the 'hyper-soft', if we want to come out on top."
The team's struggles with the 'hyper-soft' tyre in Monte Carlo undermined them in qualifying, but their strategic approach enabled Hamilton to finish third and extend his record run of points-scoring races to 31.
The 33-year-old Briton, who loves spending time in North America where he has additionally won the United States Grand Prix four times, arrived in Montreal on Tuesday night after visiting California, reportedly to check on his dogs Roscoe and Coco, and New York.
Vettel, winless in four races, finished second for Ferrari in Monaco. He has won before in Montreal, in 2013 with Red Bull, and was unlucky that a tactical error undid Ferrari's strategy with him in 2016.
Hamilton will know he and Ferrari remain a serious threat in what is expected to be a far more entertaining affair than the dull procession in Monte Carlo, even if Kimi Raikkonen faces a potential distraction after a Canadian waitress filed a lawsuit against him for touching her inappropriately in 2016. The Finn, 38, has denied the claims and filed a counterclaim.
It will be a memorable weekend also for two-time champion Fernando Alonso, who is entered for his 300th Grand Prix and, potentially, his 298th start.
He will join Brazilian Rubens Barrichello, Briton Jenson Button, the 2009 champion, and seven-time champion Michael Schumacher in the exclusive '300' club.

"It is going to be challenging," said the McLaren man. "It's a tough circuit with long straights and our lack of speed may be a penalty for us."