The 91原创 Thunder drew first blood at the Mann Cup.

After falling behind 2-0 three minutes into game one, the Thunder rallied to score 11 of the next 12 goals, defeating the Brampton Excelsiors 11-3 on Wednesday night at the 91原创 Events Centre.

The entire best-of-seven senior A lacrosse Canadian championship series is being played at the LEC.

Jarrett Davis and Zach Greer got Brampton, the Ontario Major Series Lacrosse champions, on the board early, but the Thunder responded with two quick goals in 64 seconds from Kyle McEwen and Alex Turner.

Dave Campbell gave Brampton one more lead, but Turner tied the score again and then Andrew Potter potted the eventual game-winner.

Leading 4-3 after one period, 91原创 took control in the second with Rob Van Beek, Jamie Lincoln and Athan Iannucci scoring goals.

Iannucci, Turner, Jarrett Toll and Van Beek added third period goals.

Despite the win, Thunder coach Rod Jensen knows his team has to be better.

"I know we had a really big margin of victory, but they were missing some really good players in their line-up," he said, referring to top scorer Dan Dawson and goalie Anthony Cosmo.

The pair were among a handful of Excelsiors players who missed the opener, but are expected back in the line-up soon.

"Obviously we got the outcome we wanted (but) it was a funny game," Jensen said.

"It was not very intense; both teams were maybe sparring a little bit, but quite frankly, I think we have to really pick up our intensity and our execution."

He referred specifically to the team throwing too many errant passes.

But the Thunder will gladly take the series-opening victory.

"You scrap, you claw, you take anything you can get," he said.

"The good thing is we are not taking anything for granted (and) we know we can get better.

"We know we are in for a heck of a battle."

One area that did impress the coach was the Thunder's defence and goaltending.

"They were really stretching us out (but) we adjusted (after falling down 2-0)," he said. "And Brodie (MacDonald) has been like that all year; he is going to stop those shots from those angles.

"They had a couple of good looks, but I thought we kept them to the outside."

Brampton coach Mike Haser said his team will work on some things in practice prior to game two.

"We just have to make adjustments and come back hopefully a lot better (in game two)," he said.

Haser remained tight-lipped as to when he would have his full complement of players.

Game two goes Thursday (Sept. 8) at 7:45 p.m. with games three and four on Saturday and Sunday.