Bayer Leverkusen forward Son Heung-Min has come back to haunt his former club Hamburger SV, scoring a hat-trick to help Sami Hyypia's team shade an eight-goal thriller and keep pace at the top of the Bundesliga.
Son wasted little time in breaking the deadlock at the BayArena, darting inside the penalty area before finding the back of the net with a measured finish.
The South Korean then used his pace to catch Hamburg attempting to play offside high up the field, breaking clear to round Rene Adler and double his tally seven minutes later.
Hamburg managed to respond quickly and reduced the deficit through Maximilian Beister, with Pierre-Michel Lasogga then equalising straight after the interval with a clinical finish from close range.
Leverkusen restored their advantage six minutes later as Son completed his hat-trick, before Stefan Kiessling profited from slack marking to seemingly put the game beyond doubt.
Once again Hamburg caught the hosts cold to reduce the deficit to 4-3 as Lassoga's second set up a grandstand finish, but Bayer held firm in a frantic finale as Gonzalo Castro finally secured a home win with Leverkusen's fifth in added time.