Match ends, West Bromwich Albion 1, Arsenal 1.
Jack Wilshere's second-half strike earned Arsenal a point at West Brom and returned the Gunners to the top of the Premier League on goals scored.
The Baggies took the lead when an unmarked Claudio Yacob headed home Morgan Amalfitano's cross.
Nicolas Anelka missed two good chances to double the home side's lead shortly before Wilshere's deflected 20-yard shot levelled for Arsenal.
Olivier Giroud almost won it for the visitors but Boaz Myhill denied him.
Defeat would have been harsh on Steve Clarke's side, who followed last weekend's victory against champions Manchester United with a slick performance which saw them become the first team to take points off Arsenal since Aston Villa won at Emirates Stadium on the opening day.
The Baggies were composed in possession and a constant threat in the final third as the fluid movement and creativity of their front four continually exposed the Arsenal defence.
England Under-21 international Saido Berahino, who scored the winner at Old Trafford last week, produced another excellent display up front while Amalfitano and Stephane Sessegnon linked well with Anelka to cause the visitors problems.
But Arsenal also had their moments and showed a resilience which is marking them out as genuine title contenders.
They were indebted to goalkeeper Wojciech Szczesny early on, the Pole getting down well to deny Berahino, who cut inside and fired in a low shot.
At the other end, Aaron Ramsey had Arsenal's best opportunity and the impressive Myhill reacted instinctively to beat the ball clear after his fellow Welshman's shot found its way through a crowd of players.
That save lifted the hosts, who went straight up to the other end and took the lead - Amalfitano putting an inch-perfect cross into the box from the right for Yacob to head home from six yards out.
The hosts pressed for a second after the break and former Arsenal striker Anelka miscontrolled in the area after Berahino powered past Per Mertesacker on the left.
Mertesacker was having a shaky 10 minutes - which led to him being shifted from the right side of central defence to the left - and Anelka sprinted past the German before curling a shot agonisingly wide.
Arsene Wenger's side gradually began to assert their authority in midfield and equalised in impressive style when Tomas Rosicky and Giroud combined to tee up Wilshere for his first Premier League goal in almost three years.
The England midfielder was now snapping into the tackle and spraying passes around - his clever ball forward splitting the Baggies defence and putting Giroud through, but Myhill saved well as the Frenchman tried to round him.
Both sides continued to drive forward but struggled to break through, settling for a hard-earned point which sends Arsenal into the two-week international break at the league's summit and lifts West Brom up to 12th.
- 3OlssonBooked at 54mins
- 29SessegnonSubstituted forMorrisonat 78'minutes
- 18AmalfitanoSubstituted forBruntat 89'minutes
- 39AnelkaSubstituted forLongat 69'minutes
- 10WilshereBooked at 45mins
- 20FlaminiBooked at 22mins
- 16RamseySubstituted forRosickyat 59'minutes
- 12GiroudSubstituted forBendtnerat 85'minutes
- Lee Mason
- Shots on Target
Second Half ends, West Bromwich Albion 1, Arsenal 1.
Foul by Tomas Rosicky (Arsenal).
James Morrison (West Bromwich Albion) wins a free kick in the defensive half.
Foul by Jack Wilshere (Arsenal).
Liam Ridgewell (West Bromwich Albion) wins a free kick in the defensive half.
Substitution, West Bromwich Albion. Chris Brunt replaces Morgan Amalfitano because of an injury.
Attempt saved. Mathieu Flamini (Arsenal) right footed shot from outside the box is saved in the centre of the goal. Assisted by Tomas Rosicky.
Attempt missed. Morgan Amalfitano (West Bromwich Albion) right footed shot from outside the box misses to the left. Assisted by Shane Long with a headed pass following a set piece situation.
Substitution, Arsenal. Nicklas Bendtner replaces Olivier Giroud.
Foul by Tomas Rosicky (Arsenal).
Youssuf Mulumbu (West Bromwich Albion) wins a free kick in the defensive half.
Offside, Arsenal. Wojciech Szczesny tries a through ball, but Olivier Giroud is caught offside.
Per Mertesacker (Arsenal) wins a free kick in the defensive half.
Foul by Shane Long (West Bromwich Albion).
Substitution, West Bromwich Albion. James Morrison replaces Stéphane Sessegnon.
Foul by Kieran Gibbs (Arsenal).
Shane Long (West Bromwich Albion) wins a free kick in the defensive half.
Attempt missed. Shane Long (West Bromwich Albion) header from the centre of the box misses to the left. Assisted by Morgan Amalfitano with a cross.
Attempt saved. Olivier Giroud (Arsenal) right footed shot from the right side of the six yard box is saved in the bottom right corner. Assisted by Jack Wilshere with a through ball.