London - Belgium international Kevin De Bruyne starred as Manchester City ended Southampton's unbeaten away record in the Premier League this season with a disjointed 3-1 win on Saturday.
Having lost at Juventus in the Champions League in mid-week and dropped five points in their previous two league games to slip from the summit, City needed any kind of victory to restore their momentum.
And despite the threat of a Southampton fightback early in the second half, Pellegrini's side did enough thanks to early goals from De Bruyne and Fabian Delph, and a third, 20 minutes from time, by Aleksandar Kolarov.
City saw key striker Sergio Aguero hobble off with what appeared to be an ankle injury mid-way through the second half, but Pellegrini played down the extent of the problem.
After their abject performance in losing 4-1 at home to Liverpool last weekend, City showed their intent from the start at a rain-lashed Etihad Stadium.
It looked as though they had the game won inside the opening quarter as De Bruyne scored his seventh goal of the season and Delph his first for the club.
Southampton goalkeeper Maarten Stekelenburg had already been forced to make saves from Raheem Sterling and Kolarov's curling free-kick when he was beaten by De Bruyne in the ninth minute.
The Netherlands international had no chance of keeping out De Bruyne's tap-in, but the ball would never have got that far had Maya Yoshida not conceded possession to Sterling wide on the Saints right.
The City winger was given an uninterrupted run into the box and picked out his team-mate with a low cross.
Southampton, missing suspended top scorer Graziano Pelle, did not help their cause by constantly giving the ball away in dangerous areas and with 20 minutes gone they were 2-0 down.
Steven Davis was not penalised when a header from Fernandinho struck his arm, but from the resulting corner De Bruyne teed up Delph to drill home from 25 yards with the help of a deflection off defender Virgil van Dijk.
Van Dijk tried to make amends with a fierce 25-yard shot that hit the post while City goalkeeper Willy Caballero, playing in place of the injured Joe Hart, then saved from Victor Wanyama.
City failed to heed that warning and rather than kill off the visitors -- Yaya Toure wasting a chance just before the break -- found themselves dragged back into a contest four minutes into the second half.
A quickly taken free-kick from Davis released Sadio Mane and his right-wing cross was perfectly delivered for Shane Long to head powerfully in at the far post and claim his first league goal since August.
Southampton sensed the chance of some reward and should have been level with an hour gone.
Substitute Dusan Tadic was released by James Ward-Prowse, but failed to beat Caballero with a weak chipped finish and Long's follow-up was blocked by Fernandinho.
Southampton, whose last defeat away from home in the Premier League had come at City on the final day of last season, threatened again through Tadic, whose low shot was pushed away by Caballero.
But City finally killed off any hopes of a comeback and eased the growing frustration among their supporters thanks to a goal from Kolarov in the 69th minute.
The left-back scored his second goal of the season when he controlled a lofted pass from De Bruyne and kept his composure to fire across Stekelenburg and into the bottom-right corner.
Aguero's departure was an understandable moment of concern for the home fans, but there was better news later on when influential playmaker David Silva rose from the bench to end a nine-game absence from an ankle injury.