The Langley Thunder has struck first in the Western Lacrosse Association championship series.

The defending WLA playoff champion Thunder downed the Coquitlam Adanacs 7-3 Sunday at the Langley Events Centre, in the opening game of the teams’ best-of-seven series.

The series winner will represent western Canada in the Mann Cup national championship.

If the Thunder get past the Adanacs, the local squad will make its second consecutive Mann Cup appearance.

Last summer, Langley lost to the visiting Brampton Excelsiors in the Canadian senior A final.

“We’re a confident group,” Thunder head coach Rod Jensen said. “Going into the [2011] Mann Cup helped us, because you get the feeling of what it takes to get there.”

Sunday’s game initially looked like it would go down to the wire, after the teams entered the first intermission locked in a 1-1 tie.

The Thunder took control in the second period by scoring three unanswered goals off the sticks of Athan Iannucci, Brett Hickey, and Garrett Billings (his second of the night, after he opened the game’s scoring 3:01 into the opening frame).

Langley led 4-2 after two periods of play.

“The second period was one of the most disciplined of the whole season,” Jensen said. “Everybody talks about Coquitlam’s defence and goaltending but over the past few years, we’ve had the strongest defence in the league by far, in my opinion. They have some strong left-handers [offensive players] and our right-handed defenders did a really good job led by [Brett] Mydske, [Matt] Leveque, [Matt] Wilson, and [Sam] Cook.”

Leading 5-3 late in the third period, the Thunder notched the final two goals of the night.

Joel McCready scored a pair of third-period markers for the Thunder. Rob Van Beek rounded out the game’s scoring with 59 seconds to go in regulation time.

The series shifts to Coquitlam tonight (Aug. 21), then returns to the LEC Thursday (Aug. 23).

The teams are back in Coquitlam for game four next Saturday (Aug. 25). If necessary, games will be played in Langley Aug. 27, Coquitlam Aug. 29, and Langley Aug. 31.

All games start at 7:45 p.m.

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The Thunder has been gearing up for the final since Aug. 9, when the local squad completed a four-game sweep of the fourth-place Burnaby Lakers in their semifinal series.

During the regular season, the Thunder topped the seven-team WLA with a 12-6 record.

The Adanacs finished third with a 10-8 mark.

After downing the Victoria Shamrocks in six games in their semifinal, the Adanacs find themselves in the WLA championship a year after finishing last in the WLA with a 7-11 regular season record.

This is the Thunder’s second consecutive appearance in the final. In 2011, Langley defeated the New Westminster Salmonbellies four-games-to-two to advance to the Mann Cup.