London - Son Heung-min burst out of a 19-game goal drought to help Tottenham into the League Cup quarterfinals on Wednesday, while a pair of early own-goals ruined Frank Lampard's return to former club Chelsea.
Son scored his first two goals of the season and another of Tottenham's forgotten men, Fernando Llorente, added one in a 3-1 win over West Ham in an all-Premier League London derby at the Olympic Stadium.
The reward for Tottenham: A last-eight meeting with north London rival Arsenal at Emirates Stadium in December.
While remaining a star for South Korea, which he led to a gold medal - thereby earning exemption from military service - at the Asian Games in September, Son is no longer guaranteed a first-team place at Tottenham because of fierce competition up front.
Spurs, who were playing just 48 hours after a loss to Manchester City in the Premier League, are looking to claim a first piece of silverware under Mauricio Pochettino and end what will be an 11-year wait for a trophy.
Lampard, now a manager, returned to Chelsea with his second-tier team Derby County and was trying to take down the club where he is the all-time top scorer with 211 goals after a trophy-laden 13-year spell.
Derby lost 3-2 and was ultimately undone by two own-goals in the opening 21 minutes - the first of which was scored in the fifth minute by a player on loan from Chelsea, Mikayo Tomori. The game almost went to penalties, with Derby striker David Nugent hitting the post in the final minutes.
Lampard spent time on the Stamford Bridge field after final whistle, applauding Chelsea's fans and getting plenty of cheers in return.
"There wasn't a tear in the eye, but it was emotional," Lampard said. "I did leave here quietly (in 2014), slightly out of the back door, so it's good to walk through the front door and get that."
Chelsea was drawn to play Bournemouth at home in the quarterfinals.
Arsenal set up the north London derby in the quarterfinals by beating third-tier Blackpool 2-1 in a match both teams finished with 10 men.
Stephan Lichtsteiner, with his first for the club, and 18-year-old midfielder Emile Smith Rowe scored Arsenal's goals at the Emirates before Matteo Guendouzi was sent off for a second yellow card in the 56th minute.
Blackpool reduced the deficit 10 minutes later through Paudie O'Connor, who was later shown a straight red card for a foul on Pierre-Emerick Aubameyang to end any hope of a comeback.
PULIS' MIDDLESBROUGH ELIMINATE PALACE
Tony Pulis got one over his former club when second-tier Middlesbrough beat Crystal Palace 1-0 in the other fourth-round match on Wednesday.
Lewis Wing grabbed the only goal in first-half injury time with a swerving shot from long range.
Pulis managed Palace for eight months in the 2013-14 season, helping keep the team in the Premier League.
DRAW FOR QUARTER-FINALS
Arsenal v Tottenham
Leicester/Southampton v Manchester City/ Fulham
Middlesbrough v Burton Albion
Chelsea v Bournemouth
The matches will be played in the week starting December 17.