West Ham came from two goals down to snatch a 2-2 draw from a heated London derby at Millwall.
The Lions were leading at half-time through goals from Caleb Taylor and Camiel Neghli but the visitors hit back through Mohamadou Kante and Konstantinos Mavropanos.
The Hammers, who made the short trip across the Thames sitting top of the Championship and looking for a fifth straight win, finished their first meeting with their fierce rivals since 2012 with 10 men after Kante saw red.
The Metropolitan Police had 400 officers on hand, having thrown a ring of steel around part of London to ensure there was no repeat of the violence which has marred this fixture in previous seasons.
There were no immediate reports of any trouble, while West Ham showed no appetite for a fight on the pitch in a timid first half.
Millwall may have been waiting almost 15 years for the reunion, but it took just 15 seconds for Jenson Metcalfe to set the tone, going in hard on Hammers skipper Jarrod Bowen.
In years gone by a Mark Noble, a Julian Dicks or a Billy Bonds would have reciprocated, but West Ham did not put a tackle in throughout the first half.
Millwall went ahead in the 16th minute with a suitably scruffy strike befitting the occasion after Lyndon Dykes caused chaos with a long throw into the box.
With Hammers centre-half Mavropanos off the pitch after receiving treatment, no one dealt with the ball until it fell at the feet of Mark Sykes, whose point-blank shot produced a superb stop from Mads Hermansen.
But Taïryk Arconte got to the loose ball first and lifted it back across goal for Taylor to leather home at the far post.
It took West Ham 33 minutes to have a touch inside the Millwall penalty area and it was not worth the wait as Taty Castellanos headed an Arne Engles free-kick wide.
But Millwall kept pouring forward and were inches from a second when, in first-half stoppage time, Sykes' 30-yard drive was touched on to the crossbar by Hermansen.
There was still time for Millwall to go in at half-time two ahead after another long Dykes throw, this time falling to Neghli to tuck away.
Hammers boss Nuno Espirito Santo threw on Kante and Pablo Felipe at the break to add a bit of muscle to his fragile side.
Bowen finally got a shot away in the 52nd minute, with Lions keeper Filip Marschall spilling his deflected effort on his Championship debut and Kante just unable to get to the rebound.
Marschall did well to keep out a close-range header from Pablo, but he was beaten in the 74th minute when Kante pinged a low drive into the corner.
Bowen hit the side-netting before West Ham hauled themselves level with 10 minutes left when Mavropanos headed home Manor Solomon's cross.
West Ham looked likeliest to find a winner until last man Kante was sent off for pulling back fellow sub Kyrell Lisbie as he raced through on goal.