San Jose Sharks centre Logan Couture has labelled Pittsburgh Penguins star Sidney Crosby a cheater after game two of the NHL Stanley Cup Finals.

Crosby was dominant on Wednesday as the Penguins took a 2-0 lead in their best-of-seven series against the Sharks.

The Penguins' captain won 71 per cent of the face-offs he took (17 of 24), including three of four head-to-head against Couture.

Crosby helped set up Conor Sheary's game-winning goal by winning a face-off against Joel Ward in overtime.

However, Couture said cheating was the only way to explain Crosby's prowess in the face-off circle.

"He cheats, and he gets away with it. He's Sidney Crosby," Couture told reporters, unprompted, following their 2-1 loss at the Consol Energy Center.

Explaining how Crosby is a cheater, Couture said: "He times them, and yet they don't kick him out for some reason, probably because of who he is."

Couture and Co. head to the SAP Center in San Jose on Friday as they aim to get themselves back into the series on home ice.