Oilers earn point - lose shootout
Markkanen made several unbelievable stops with the Senators buzzing around the net, attempting to jam the puck in during a scramble in front.
Edmonton finally had an opportunity to break the deadlock but Martin Gerber denied Joffrey Lupul on a backhand from the slot.
Ottawa finally got on the board as Dany Heatley's shot from the left circle beat Markkanen five hole to make it 1-0.
On the next shift, Ales Hemsky made a nice deke move in the slot while rushing up ice but couldn't get a handle on the puck at the last moment with Gerber down and out.
Craig MacTavish started to shuffle up the lines in an effort to spark his club. The line of Shawn Horcoff, Raffi Torres and Toby Petersen generated some pressure deep in the Ottawa zone and drew a penalty as a result.
Shots on goal after one period were 12-7 for Ottawa.
With Ottawa on the power play midway through the second, Markkanen held the fort to keep it a one-goal game. The Sens poured on the pressure, cycling the puck well in the Edmonton zone. The Oilers netminder made a difficult stop on a screened shot from the point.
The Oilers came close to tying it on the next shift following the penalty. Ladislav Smid picked up a pass and tried a spin-o-rama move in the slot but Gerber got a pad on his backhand shot.
Shortly after the chance, play carried back up ice and into the corner deep in the Edmonton net. Daniel Alfredsson surveyed the situation before finding Mike Fisher alone in the high slot. He corralled the puck and then wristed it under the crossbar to make it a 2-0 game.
Shots on goal after two periods were 20-16 for the Senators.
An early third-period power play resulted in a goal to get the Oilers back in the game. Petr Sykora took a pass from Hemsky in the high slot and took his time before setting up to wind up for a blast. His shot beat a screened Gerber with Smyth stationed in front.
A nice individual effort by Daniel Alfredsson just past the midway point of the third resulted in Ottawa's third of the night.
Alfredsson picked up the puck and muscled his way towards the front of the Oilers net before putting his own rebound past Markkanen to make it 3-1.
The Oilers responded with about four minutes to play in the third to make it a one-goal game once again. Chris Kelly's clearing attempt was intercepted by Sykora in the slot and he rifled it past Gerber for the goal.
The final minute involved some frantic action in front of the Ottawa net as the Oilers attempted to tie it up. Eventually, Tom Gilbert pinched in from the point and picked up the puck on a pass from Hemsky. He wristed it into the open net for his first career NHL goal to tie it up at 3-3.
In the shootout, Antoine Vermette was stopped by Markkanen but Dean McAmmond and Mike Comrie scored to lead Ottawa to the win. Ales Hemsky and Petr Sykora were both denied.