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.

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 game marked the halfway point of the truncated season for both Toronto (15-9-0) and Ottawa (12-8-4).

Wracked by injuries, the Senators have relied on some stingy defence. They came into the game ranked second only to Chicago in goals against, giving up just 1.83 a game.

Ottawa has been good at home (9-1-2) and poor on the road (3-7-2). The Leafs, conversely have profited more away (9-4-0) than at home (6-5-0).

The game marked the return of Sens wingers Milan Michalek (knee) and Mark Stone (broken finger), who was making his NHL regular-season debut.

Toronto led 2-0 after the first period, despite being outshot 14-10. But the Leafs were more dangerous and James Reimer was up to the task when Ottawa threatened.

Before the goals, came the fights.

It took just 26 seconds before mayhem erupted with six-foot-five Toronto tough guy Frazer McLaren taking on six-foot-three Dave Dziurzynski at a faceoff. McLaren ended the fight violently and decisively when he caught the Sens forward flush with a right to the chin, toppling him face down. Dziurzynski was slow getting up and eventually needed help from two teammates to skate off the ice.

Had it been the UFC, McLaren would have won knockout of the night bonus.

Sadly, Dziurzynski may or may not remember the three seconds he officially logged in his 10th career NHL game. He did not return, with the Sens citing a concussion.

It was Toronto's 23rd fighting major of the season. The Leafs came into the game one fighting major short of league-leading Columbus.

Less than five minutes later, Toronto's Colton Orr upped the ante as he engaged Ottawa's Chris Neil in what was mostly a wrestling match. The major brought Orr -- whose 108 penalty minutes against Ottawa are the most against any NHL club on his blotter -- within 19 of 1,000 NHL penalty minutes.

They stuck to hockey after that in what was a wide-open if sloppy game.

Bozak scored his sixth of the season at 6:24, handcuffing Bishop by sweeping in a shot off Ottawa backchecker Peter Regin's leg following a scuffed pass from Kessel.

Less than minute later, McClement made it 2-0 with his fourth of the season when a flubbed Nikolai Kulemin pass still found him in the slot and he snapped a shot past Bishop.

Reimer -- who has won six straight and is 9-3 on the season -- looked sharp at the other end and found a way to rob Smith from a sprawling position when the Senator found himself on the doorstep of the Toronto crease with the puck.

Later in the period, Reimer stopped a Sens' short-handed 2-on-1 rush.

Van Riemsdyk added to the lead at 1:20 of the second after Bozak outworked a Senator behind the net, allowing Kessel to send it out in front where the big Leaf drove it home for his 13th of the season.

But Ottawa quickly replied on a delayed penalty with Zibanejad banging home a rebound from in-close at 2:48 for his fifth goal, cutting the lead to 3-1. The Senators looked better in the second period.

Smith made it interesting, cutting the deficit to 3-2 at 1:40 of the third period. Left alone in front of the net, he poked in a rebound of Chris Phillips' shot from the point for his first of the season.

Kessel restored a two-goal lead at 3:42, with a low wrist shot from the faceoff circle on the power play for his sixth of the season. After being shut out in the first 11 home games this season, he has now scored back to back.

Kadri made it 5-2 when Bishop failed to control Kadri's shot at 10:18. It was the Leafs sniper' 10th of the season and fifth in three games.

Unmarked, Alfredsson had time to measure his shot and beat Reimer for his fifth of the season at 12:08 to ignite another mini-comeback.

Ottawa came into the ACC on the back of three straight losses -- in overtime in Boston, in regulation against Philadelphia and via shootout Sunday at the New York Islanders.

Toronto had won two straight, beating the Devils and Islanders (in OT).