Oscar helped Chelsea draw a line beneath Juan Mata's departure with a fine free-kick in a 1-0 win over Stoke City in the FA Cup fourth round on Sunday.
The Brazilian had dislodged Mata from his position as Chelsea's main playmaker, prompting the Spaniard to join Manchester United, and the quality of his goal demonstrated why manager Jose Mourinho rates him so highly.
The Blues failed to add to Oscar's first-half effort despite hitting the woodwork twice, although it was a largely comfortable victory, with Stoke rarely threatening to score an equaliser and force a replay.
Chelsea's reward is a mouthwatering fifth round trip to Premier League rivals Manchester City.
Mourinho opted to rest a number of senior players including John Terry and Petr Cech, but his decision to include Samuel Eto'o in his starting line-up raised eyebrows.
The forward scored a hat-trick in the 3-1 victory over Manchester United seven days previously, but the manager had been expected to rest Eto'o and hand Demba Ba a rare start.
However, Eto'o wasted little time justifying Mourinho's decision, quickly impressing himself on the Stoke back-line and drawing the foul that allowed Oscar to break the deadlock in spectacular style.
Eto'o's smart turn and shot in the second minute suggested this would be a long afternoon for Stoke, who were hoping to repeat their Premier League victory over the Blues in early December.
The visitors' initial response suggested otherwise, with Peter Crouch heading wide after getting ahead of his marker David Luiz three minutes later.
Stoke struggled to put Cech's replacement Mark Schwarzer under real pressure, but they matched Chelsea in the midfield areas for long periods.
Chelsea, though, looked capable of capitalising on any Stoke error and should have taken the lead from a breakaway after Marco Arnautovic gave the ball away carelessly inside the home half.
Then, when Erik Pieters was penalised for a tackle from behind on Eto'o, Oscar produced a memorable free-kick that gave Mourinho's side a 27th-minute lead.
Stoke complained angrily that the decision to penalise Pieters was harsh and television replays suggested they had a point.
Their sense of injustice was fuelled when Oscar lifted the free-kick over the wall and into the top-left corner, bending so much that it wrong-footed Stoke goalkeeper Asmir Begovic.
Begovic was back in the side after a six-game absence with a broken finger, but no blame could be laid at his door.
Having finally broken through Stoke's defence, Chelsea took control of the remainder of the first half, although Stephen Ireland did provide a scare when he fired a left-foot shot into the side-netting.
Oscar should have added a second goal when he broke into Begovic's area and beat the goalkeeper with a powerful shot that cannoned to safety off the upright.
And Chelsea maintained their momentum after the break when Andre Schurrle found himself in a similar position before firing against the crossbar.
Stoke offered little in return and could have been on the end of a more comprehensive defeat if Eto'o had not missed from close range late on, while Ramires had a penalty appeal turned down.