Sergachev factored on each of the Lightning's four first period goals. He opened the scoring at 1:23, assisted on goals from Nikita Kucherov and Nick Perbix midway through the period, before adding a power play goal late to cap off a dominating 20 minutes.
After Washington scored the lone goal of the second period, the teams evenly split four goals in the third, including the first of Cole Koepke's NHL career.
The Bolts will remain home into next week and are back in action on Tuesday against Dallas.
Scoring Summary
1st Period
TBL 1, WSH 0
1:23 Mikhail Sergachev (3) - Steven Stamkos, Nick Perbix
The Lightning got off to a fast start, grabbing the lead less than 90 seconds into the game on a shot from the left point that snuck through traffic and past Darcy Kuemper.
TBL 2, WSH 0
8:19 Nikita Kucherov (7) - Mikhail Sergachev, Brandon Hagel - PPG
The power play notched a much-needed goal on their first chance of the game. Off a broken play, the puck was worked to Sergachev at the point, and he teed up Nikita Kucherov for a big one-timer from the right circle.
TBL 3, WSH 0
11:12 Nick Perbix (3) - Alex Killorn, Mikhail Sergachev
Nick Perbix used a lucky bounce to extend his point streak to four games. From along the far wall, Perbix threw the puck toward the front of the net and had it deflected into the Washington net off Erik Gustafsson's skate.
TBL 4, WSH 0
16:22 Mikhail Sergachev (4) - Steven Stamkos, Nikita Kucherov - PPG
Sergachev's second goal of the night capped a dominating first period for the Bolts and himself. Sergachev wound up a one-timer from the point for a power play goal that extended the Lightning's lead to 4-0 and marked his fourth point of the opening period.
2nd Period
TBL 4, WSH 1
18:04 Conor Sheary (6) - Evgeny Kuznetsov, Anthony Mantha
An odd man rush materialized quickly for the Caps down low, and Conor Sheary swept home Evgeny Kuznetsov's feed to get Washington on the board.
3rd Period
TBL 5, WSH 1
13:15 Cole Koepke (1) - Brayden Point, Pat Maroon
Cole Koepke's first career NHL goal came in odd fashion and took a review to become official. At the 13:15 mark, Koepke swept a backhander past Charlie Lindgren, but the puck was in and out of the net so quickly that play continued. Seconds later, Brandon Hagel ended up scoring, but replay revealed Koepke's goal had actually gone and that's what ended up counting.
TBL 5, WSH 2
16:59 Lars Eller (3) - Marcus Johansson, Trevor van Riemsdyk
Lars Eller made it a three-goal game again when he snapped a shot past Andrei Vasilevskiy from the right circle.
TBL 6, WSH 2
17:16 Nick Paul (5) - Alex Killorn - ENG
Following Eller's goal, the Caps opted to pull Lindgren to try and get back in the game, but Nick Paul quickly found the empty net to put things out of reach.
TBL 6, WSH 3
17:58 Garnet Hathaway (2) - Nic Dowd
Garnet Hathway rounded out the scoring with just over two minutes remaining in regulation.
