Twice during the extra frame, Cogliano took the crowd's breath away as he just narrowly missed the net on several opportunities.
Finally, with 4.9 seconds left to play in OT Gagner passed it from behind the net to his teammate in the slot. Cogliano wristed it in for the goal.
"I got a lucky break right in front of the net and just put it in," Cogliano said.
The Oilers looked like they were going to run away with the game early on, racing out to a 3-0 lead in the game's opening 8:40 but St. Louis battled back to tie the game and force overtime.
"We had a lot of mistakes in our end and didn't play our best game," Cogliano remarked. "But we'll take it."
Edmonton's fast start began when Zack Stortini rifled a shot from the top of the right circle 2:58 in, beating Manny Legace high glove side to give the host Oilers a 1-0 lead.
The Oilers continued to put pressure on the Blues, resulting in gaining the game's first power play. Paul Kariya was sent off for holding the stick of Fernando Pisani.
14 seconds later, Eric Brewer cleared the puck over the glass from his own zone and received a delay of game penalty, giving Edmonton a two-man advantage.
58 seconds into the five-on-three, Sam Gagner found Jarret Stoll in the high slot. He one-timed a blast by Legace to increase Edmonton's lead to 2-0.
Hard work by Nilsson deep in the Blues zone resulted in Yan Stastny getting sent off for slashing. Edmonton then went on their third power play of the game.
This time, it only took the Oilers 31 seconds to connect on the power play. Gagner centered the puck where it bounced in off a Blues defender in front and into the net.
With eight minutes left in the first, Ales Hemsky danced around the Blues defenders as he skated into the St. Louis zone. He managed to get close to Legace where his deke attempt was denied.
Marc Pouliot was sent to the box for hooking late in the period, giving St. Louis their first power play and it only took them nine seconds to capitalize.
Brad Boyes dumped the puck in and it took a wild bounce off the boards in the corner. Garon tripped up, giving Andy McDonald an open net to put the puck in.
Shots on goal after the first period were 10-7 for Edmonton.
Lee Stempniak scored 40 seconds into the second period after he batted in a pass from David Backes that snuck inside the post on the blocker side of Garon.
Midway through the period, the Blues put some sustained pressure on the Oilers as momentum in the game started to swing in their direction. St. Louis had Edmonton's fourth line pinned deep in their own zone for well over a minute and the defence pairing of Smid and Greene for almost two full minutes.
On the next shift, Brad Boyes connected from short range to complete the comeback for the Blues, tying the game up at 3-3.
Late in the first, the Blues looked to have the go-ahead goal gift wrapped for them when Paul Kariya had a wide open net and the puck on his stick at the right faceoff dot. With Garon out of position, Kariya's shot was blocked on its way to the net by Denis Grebeshkov.
Shots on goal after two periods were 21-16 in favour of the Blues.
Cam Janssen took a roughing penalty early in the third period but the Oilers were unable to do any damage on the power play in the subsequent two minutes.
Edmonton almost regained the lead just past the third period's midway point. Gagner, Cogliano and Nilsson tried to complete a three-way passing play but Nilsson couldn't get his stick on the feed at the top of the crease in front of Legace.
Moments later, Smid was ticketed for high sticking, putting the Blues on the power play with a chance to take their first lead of the night.
While shorthanded, Pisani carried the puck up ice and cut in front of the Blues net but lost control of it just as he was about to make his move.
Edmonton had another chance moments later when Smid came out of the box. He outskated the Blues defender and skated in front where Legace made a nice save on his backhand attempt.
The game was tied 3-3 at the end of regulation time with St. Louis outshooting Edmonton 27-20.
55 seconds into the extra frame, Hemsky drove towards the net before getting shoved by Barrett Jackman at the last minute. He ran into Legace shaking up both himself and the Blues goaltender.
NOTES: Cogliano's third overtime winner in three games set a new NHL record... Tonight was Edmonton's 23rd overtime game of the season, tying them with Atlanta for the league lead. The Oilers are 18-5 overall in extra time (14-3 in shootouts and 4-2 in sudden death OT).
Edmonton's Matt Greene trips up Blues forward Jay McClement during the second period.
- photo by Greg Skafte edmontonoilers.com