MONTREAL, Canada - Sebastian Vettel believes Ferrari has regained form and is back among the front-runners after Fernando Alonso topped the times in Friday afternoon's second free practice ahead of Sunday's Canadian Formula 1 GP.The defending triple World champion said he felt the scarlet scuderia, with widespread support in Montreal, would be hunting victory again. The team had endured a disappointing Monaco GP two weeks earlier - Alonso was seventh.MERCS A THREATThe double World champion Spaniard topped the times ahead of Mercedes' Lewis Hamilton, leaving Vettel admiring the rediscovered pace.He said he also felt that Monaco winner Mercedes, which has started from a hat-trick of poles, will also be a threat through either Hamilton or Monaco winner Nico Rosberg. Or both.Vettel said: "On one lap, if you look at the time sheets, Mercedes was again very, very quick, and Ferrari looks competitive on both long and short runs. I think those will be the main two rivals but don't forget Lotus - its cars can go further (on tyres) than anybody else."So, for this race, it is difficult to say, but you need to keep an eye all those teams."'STRONG OVERALL'Vettel's Red Bull team mate Mark Webber, fourth fastest while Vettel was down in seventh, said: "On the short run we have some room for improvement and Mercedes looks very, very quick again but I felt we were pretty strong overall."In the wet, on the intermediate tyres I felt comfortable straight away. It is always tricky around here to get everything together in such conditions - if you're not comfortable you can bleed a lot of lap time but the car seemed good." Stay with Wheels24 for the 2013 Canadian GP weekend.