Chelsea staged a spectacular comeback with three goals in nine second-half minutes to beat Southampton 3-2 on Saturday.
The win revives the London club’s faint hopes of a top-four Premier League finish as Saints remained in the drop zone.
Substitute Olivier Giroud scored twice, his first league goals for Chelsea, either side of an Eden Hazard strike.
The goals came just when it looked like Antonio Conte’s visitors lacked the fight against opponents who scrapped for every tackle at St Mary’s.
Less than 10 minutes after coming off the bench just past the hour, Frenchman Giroud met Marcus Alonso’s cross for his first goal.
He then shot clinically from the edge of the area for the winner as Saints paid for some sloppy defending.
The win moved Chelsea within seven points of fourth-placed London rivals Tottenham Hotspur, who host Manchester City later on Saturday, and Liverpool who welcome Bournemouth
“The most important thing is you never give up,” said Giroud, who also scored for his previous club Arsenal at Southampton earlier this season.
“As long as it is mathematically possible to finish in the top four we will keep battling. It was important to show some character.”
Southampton looked to be cruising towards a win that would have lifted them up to 17th and out of the relegation places, at least temporarily.
Dusan Tadic and Jan Bednarek put them two goals ahead after an hour.
Bednarek’s goal was his first in the top flight in only his third game for the club.
The 22-year-old Pole met James Ward-Prowse’s cross on the half-volley to leave Chelsea, who might have had Alonso sent off for a stamp on Shane Long, in a desperate position.
But Saints have struggled to hold on to leads this season and collapsed halfway through the second period, conceding three goals for the fourth successive league game.
Southampton manager Mark Hughes now faces a desperately difficult fight to keep his team in the Premier League.
“As has been the case all year, apparently we’ve got a soft underbelly,” he said.
“When the momentum shifts against us we can’t get a platform and wait until the momentum swings our way again.”
With five games remaining, they have been left three points below the safety zone before the rest of the weekend matches.
Southampton face Chelsea again in the FA Cup semi-final at Wembley next weekend.