London - Guus Hiddink enjoyed his first victory since taking over as Chelsea interim manager as the troubled Premier League champions crushed Crystal Palace 3-0 on Sunday.
After draws against Watford and Manchester United following his arrival as short-term replacement for the sacked Jose Mourinho, Hiddink was at last able to celebrate three points at Selhurst Park.
Oscar opened the scoring in the first half before Willian's cracker and a Diego Costa strike extended Chelsea's unbeaten run since Mourinho's departure to four matches.
In such turmoil for much of a season ruined by the breakdown of Mourinho's relationship with his squad, the Blues are slowly getting back in the groove under Hiddink and moved six points clear of the relegation zone after their first away league success in eight attempts.
After climbing into contention for a European place, Palace's first defeat in seven matches left Alan Pardew's men without a win or a goal in their last three games.
With torrential rain lashing Selhurst Park, Palace forward Wilfried Zaha went close early on with a low strike that skimmed off the slick pitch.
Eden Hazard saw a long-range effort deflected wide at the conclusion of Chelsea's first serious attack, but the Belgium playmaker began limping immediately after the shot.
Hazard, lambasted by Mourinho for not trying to play on when injured at Leicester last month, briefly carried on but in the 15th minute he decided he needed to come off.
While Hazard's commitment to the cause has been questioned in the past, on this occasion the 24-year-old seemed in genuine discomfort.
Palace defender Damien Delaney had a pair of headers saved by Thibaut Courtois as the hosts tried to take advantage of Chelsea's tepid start.
But crucially Palace striker Frazier Campbell scuffed wide from Jason Puncheon's cross midway through the half and Hiddink's team finally awoke from their slumber to snatch the lead in the 29th minute.
Hiddink had made two changes from Monday's draw at United as Costa returned from suspension and Cesc Fabregas came in for Nemanja Matic.
Both repaid their Dutchman's faith with decisive contributions to the opener.
Fabregas was the architect with a pass that sent Costa racing away from Delaney down the right edge of the Palace area.
Looking up, Costa unselfishly ignored the chance to shoot himself and, with goalkeeper Wayne Hennessey out of position, the Spain striker pulled the ball back to Oscar, who had the simple task of slotting home from close-range.
Hiddink had called for players other than Costa to take the responsibility of scoring and Oscar's fifth goal of the season was a well-timed response from the Brazilian.
Cesar Azpilicueta almost made it two when he beat the Palace offside trap, surging clear to test Hennessey with a powerful strike that drew a fine stop from the Palace keeper.
While Palace were typically tenacious in their tackling, they were clearly missing the class of France midfielder Yohan Cabaye and influential winger Yannick Bolasie, absent through suspension and injury respectively.
Kurt Zouma should have doubled Chelsea's lead when he rose highest to meet Willian's free-kick, but the defender couldn't keep his header on target.
However, Zaha was unable to summon the power or accuracy to beat Courtois from a promising position and Willian made Palace pay in the 60th minute.
When Scott Dann tried to block Oscar's progress the loose ball ran to Willian and the Brazil winger smashed a superb strike high into the roof of the net from 20 yards.
Costa wrapped up Chelsea's biggest league win of the season six minutes later when he claimed his seventh goal of the season from close-range after Hennessey pushed Willian's shot into his path.