Hibernian need to "stay focused and ignore the noise" after returning to third in the Scottish Premiership, says head coach Jack Ross.
A second-half header from Ryan Porteous and a Martin Boyle penalty downed 10-man St Mirren who had goalkeeper Jak Alniwck dismissed in the first half.
Jon Obika's goal gave the hosts hope, but Hibs saw the game out to move back above Aberdeen.
"You are only third if you are a good side," said Ross.
"That's three wins from the last four games. We've had bumps along the way, but we've done a lot of things well this season.
"At this stage of the season, it's just about grinding out wins."
The visitors enjoyed the majority of possession early on without troubling the St Mirren backline, and it was instead the hosts who had the real first sights of goal as striker Kristian Dennis lashed two half volleys wide of either post.
As the half wore on, Goodwin's men looked comfortable in defence but, unlike their previous two games, the Paisley club were not posing a direct threat to their opposition's backline.
That lack of attacking spark was hampered further with Alnwick's dismissal on 36 minutes.
Boyle latched on to a casual back pass from Jake Doyle-Hayes and knocked the ball past the onrushing Alnwick, who clattered the Australia international, leaving referee Alan Muir no choice but to show the red card. Substitute keeper Dean Lyness entered for his first league appearance since May 2019.
Both Porteous and Kevin Nisbet - who were benched again - were on the pitch within five minutes of the second half, with the former coming on at half-time to replace Darren McGregor, and the impact of the pair was almost instant.
Nisbet's teasing low ball had to be steered behind by the St Mirren backline, and from the corner Porteous was on hand to power home a near-post header.
Christian Doidge then saw a header tipped over by Lyness before Marcus Fraser tripped Jamie Murphy in the area, allowing Boyle to convert from the spot.
Despite being down to 10 men, the hosts responded with the fight we have become accustomed to.
Dylan Connolly broke down the left and provided Obika with an inch-perfect ball to finish as Murphy saw a strike from the edge of the area crash off the outside of Lyness' left-hand post at the other end.
In the closing stages, Hibs had to dig to secure their fifth straight top-flight win in Paisley.
Man of the match - Martin Boyle
What did we learn?
Goodwin's decision to make four changes to the side that beat Celtic on Saturday was a bit of a head scratcher pre-game, and it appeared to have an impact on St Mirren's attacking zip in the first half.
Connolly has been key to St Mirren's attack in recent weeks, and his second-half introduction gave the hosts a threat that was just not there in the first period. But it was too late as they were down to 10 men by then.
As for Hibs, Ross' management of Nisbet and Porteous looks to have a worked a treat. The decision to take both players out the spotlight looks justified, and they provided a vital contribution full of hunger and determination in the second half.
With the window now closed, and his side back in third, Ross will hope both players have full focus on their current club from now until May.
What they said
St Mirren manager Jim Goodwin: "11 v 11, we were the better team. We were well on top in terms of controlling possession. If we kept 11 men on the park I don't think we would've lost the game.
"From that moment [red card] on against a good Hibs team you're going to be up against it. Credit to the players, they never gave up."
Hibernian head coach Jack Ross: "The only real moment of slackness in the game resulted in the concession of the goal.
"After that it become more anxious than it should've been, but overall I'm really pleased with the result and the performance."
What's next?
Both sides return to Premiership action on Saturday (15:00 GMT) as St Mirren welcome Kilmarnock and Hibernian host Aberdeen.