On a strength of an ugly knockout and an early lead, the Toronto Maple Leafs won the latest instalment of the Battle of Ontario by holding on to beat the Ottawa Senators 5-4 in NHL action Wednesday.

The win gives Toronto a 2-1 advantage in the season series.

There were scary moments early in the game, when Senators forward Dave Dziurzynski was knocked out cold in a fight with the Leafs' Frazer McLaren.

Both Dziurzynski and McLaren connected with a couple of haymaker punches before a shot by the latter sent Dziurzynski crashing to the ice chin-first.  The Ottawa player lay motionless on the ice for several moments before being helped off the ice by the team's trainer and several teammates.

Tyler Bozak, Jay McClement, James van Riemsdyk, Phil Kessel and Nazem Kadri scored for Toronto before a crowd of 19,412 at the Air Canada Centre. Mika Zibanejad, Zack Smith, Daniel Alfredsson and Colin Greening replied for Ottawa, which fell behind 3-0 before fighting back in the third to make it 3-2 early and 5-4 late.    

The Leafs had difficulties burying the visitors and found themselves under the cosh late in the game after Sens captain Alfredsson made it 5-3. Greening then stuffed in the puck to make it 5-4 at 18:03 with Sens goalie Ben Bishop on the bench.    

As usual, Stompin' Tom Connors' ``The Hockey Song'' was played midway through the third period.

It made for a sad interlude this time, given news during the game that the Canadian music icon had passed away at 77.

``Stompin' Tom, you'll be missed. Thanks for all the memories and the greatest hockey song ever,'' PA announcer Andy Frost said during the song.

(The Canadian Press, with files from James Moore)