After six weeks out with a hamstring injury, Bellerin – named captain for the game by Mikel Arteta – curled home from 18 yards with three minutes remaining after Cesar Azpilicueta thought he had won the game for the Blues.
Chelsea took the lead in the 28th minute when Jorginho slotted home a penalty after David Luiz was shown a red card on his return to Stamford Bridge for bundling over Tammy Abraham in his attempt to bail Shkodran Mustafi out for a loose pass.
Arsenal did well to stay in the game and after Gabriel Martinelli cancelled out the opener, and Bellerin ensured Chelsea's jubilation following Azpilicueta's 84th-minute volley was short-lived.
Callum Hudson-Odoi was lively early on and, after his delivery ended with Abraham sending a header too close to Bernd Leno, he hit the crossbar when curling the ball in from the left wing.
The Blues got the goal they deserved when Abraham latched onto Mustafi's loose pass and rounded Leno before being taken down by David Luiz, with Jorginho coolly slotting the penalty into the bottom-right corner.
Arteta reshuffled his pack instead of using a substitute and Chelsea struggled to stay on top.
Martinelli punished the Blues in the 63rd minute. He latched onto Mustafi's headed clearance from a corner, raced from well inside his own half and placed a composed finish beyond Kepa Arrizabalaga after N'Golo Kante's costly slip.
Chelsea pushed for a winner late on and thought they had it when Azpilicueta stabbed Hudson-Odoi's cross past Leno at the near post.
However, the Gunners quickly hit back with Bellerin cutting inside Abraham, who appeared to be struggling with an injury after sliding into the hoardings at the other end, and guiding the ball into the bottom-left corner.
Substitute Michy Batshuayi had a chance to clinch all three points for Frank Lampard's men, but he miscued wide to leave the Stamford Bridge crowd deflated.
What does it mean? Blues still struggling at home
Stamford Bridge used to be a fortress for Chelsea, but they have found it difficult to pick up positive results on home soil this season. A frustrating draw against the Gunners means they have won just two of their past six Premier League home matches.
Martinelli more than a capable deputy?
A three-game ban for Pierre-Emerick Aubameyang made it look like Arsenal would struggle for goals, but Martinelli has scored in the two games the Gabon international has missed. He became the first 18-year-old to score in successive matches for the Gunners since Nicolas Anelka in January 1998 and deserves to retain his place when Aubameyang returns.
Mustafi a mess
Things were made much more difficult than they ought to have been for Arsenal because of Mustafi's woeful backpass in the first half. He may have ended the game with an assist thanks to Martinelli's lung-busting run, but the Gunners cannot rely on him at centre-back for the long term.
Key Opta Facts
- Chelsea have lost more points from winning positions against Arsenal in the Premier League than they have vs any other side in the competition (33).
- Arsenal had just two shots in this game, scoring with both of them.
- The Gunners have been shown more Premier League red cards against Chelsea than they have vs any other side in the competition (8).
- Arsenal have scored four Premier League goals from outside the box against Chelsea at Stamford Bridge – three of these have been netted by full-backs (Nigel Winterburn in 1997, Sylvinho in 2000 and Bellerin).
- David Luiz became just the second player to be sent off against Chelsea in the Premier League having previously played for the Blues in the competition, after Vinnie Jones in December 1995.