Alexander Perezhogin pounced on a defensive mix-up in overtime to give Avangard Omsk a 2-1 comeback win over Dynamo Moscow, putting his team 3-1 up in the Gagarin Cup final series.
It was the third winning goal from Perezhogin in the series so far, and the most valuable yet, putting his team within one victory of a first KHL championship title.
The team can seal it on home ice Saturday.
Dynamo forward Artyom Chernov's sixth-minute slapshot into an open net gave the home team the lead.
Avangard goaltender Karri Ramo made a reflex save from Dmitry Pestunov's effort later in the period.
Dynamo swarmed all over the Avangard net in the second but failed to convert five-on-three pressure into goals, and it was the visitors who scored through Alexander Popov when the teams were back to even strength.
Popov lashed the puck home from Perezhogin's well-timed assist.
Popov turned provider in a bad-tempered third period as Avangard broke quickly but Martin Skoula's shot rebounded off the frame on a four-on-four.
Avangard's Alexander Nesterov flicked against the frame as the teams entered overtime.
Ten minutes in, Dynamo's Leo Komarov allowed the puck to skip under him for Perezhogin to turn and send it underneath Alexander Yeryomenko in the Dynamo goal, sealing victory.
The Omsk team drew first blood in the series last week, Perezhogin's third-period goal snatching a 2-1 win in the opener on home ice. But Dynamo Moscow reversed that score in the second to level it thanks to Leo Komarov's controversial second-period goal.
Avangard went 2-1 up on Tuesday on a single Perezhogin goal.