Liverpool moved to within two points of second-placed Manchester United after goals from Roberto Firmino and Mohamed Salah secured a comfortable victory.
Brazil forward Firmino gave Liverpool an early lead with his 20th goal of the season when he finished off a counter attack after being teed up by Salah.
Southampton then twice brought saves out of Reds goalkeeper Loris Karius, before Liverpool added a second through Salah after he exchanged passes with Firmino.
It was the Egypt international’s 29th goal of the season for the club from 36 appearances.
Liverpool looked the more likely to score again after half-time as Southampton rarely threatened.
“The second half was really bad. The people see our reaction on the pitch and the players feel the reaction,” Pellegrino said.
“The anxiety in my players was really high. We understand the emotions of the fans but we have to keep going.”
The win ensured Liverpool took advantage of Manchester United’s 1-0 defeat by Newcastle earlier on Sunday and leapfrogged Tottenham back into third place.
Southampton drop into the relegation zone, a point behind Huddersfield who beat Bournemouth 4-1, with further scrutiny of Pellegrino’s position likely.
Source: Daily Sports