Match ends, Ipswich Town 1, Brentford 1.
Ipswich wasted the opportunity to leapfrog Brentford back into the play-off places despite Daryl Murphy's 22nd goal of the season.
Striker Murphy forced the ball home following a corner to give Mick McCarthy's side an early lead.
Jonathan Douglas nodded an equaliser after recalled goalkeeper Dean Gerken saved Stuart Dallas's initial effort.
Murphy shot over an open goal after the break and later failed to beat Button one-on-one as Brentford stayed sixth.
The draw - only the fifth of the season for the London club - kept them one place and one point above Ipswich.
|Overdue trip to Portman Road|
|Brentford's visit to Ipswich was their first since 2004 and their first in the league since a Division Three (South) game in September 1956|
|They have a poor record against Ipswich, having lost six of the nine previous meetings - with their only win back in November 1955|
The two sides went into the game with a marked contrast in their recent form, Brentford having won three and lost one since the announcement that boss Mark Warburton will leave the club at the end of the season, while Ipswich had won once and suffered three defeats in their last four.
Town started the stronger, however, with the Brentford backline looking uneasy and went ahead when Christophe Berra headed down Richard Chaplow's corner and Murphy turned the ball home.
Murphy hit the side-netting from a tight angle soon afterwards and Jonathan Parr drove left-footed across the face of the goal before the Bees slowly began to assert themselves going forward.
Alex Pritchard forced a good save from Dean Gerken diving to his left, but the Ipswich keeper could do little about Douglas's equaliser and the Bees almost made it two when Andre Gray flashed a shot wide.
Murphy had a gilt-edged chance immediately after the break, only to clear the bar from five yards after the lively Parr played the ball to him.
Button did well to deny Murphy after he ran onto a long ball from Tyrone Mings and later produced another good save to prevent sub Teddy Bishop snatching a winner.
Ipswich manager Mick McCarthy: "It is a bonkers league with Derby drawing today and Middlesbrough losing.
"It is going to go to the last game, the last minute.
"If we keep playing like that, we will win more than we lose and we will probably be in the top six."
Brentford manager Mark Warburton: "We have been in the top six since November - something that speaks volumes for my players.
"I thought we looked good when we got the ball down but this league is all about tough challenges.
"We are not a big physical team but the players stood up to Ipswich. I have told my players they are just 10 games from the Premier League, the promised land."
- 14ChaplowSubstituted forBishopat 64'minutes
- 2ParrBooked at 82mins
- 20SearsSubstituted forWoodat 64'minutes
- 10OdubajoBooked at 84mins
- 29MooreSubstituted forDeanat 71'minutes
- 20DiagouragaBooked at 81mins
- 8DouglasBooked at 52mins
- 21PritchardBooked at 37mins
- 18JudgeSubstituted forJotaat 67'minutes
- 19GraySubstituted forLongat 75'minutes
- Scott Duncan
- Shots on Target
Second Half ends, Ipswich Town 1, Brentford 1.
Harlee Dean (Brentford) wins a free kick in the defensive half.
Foul by Chris Wood (Ipswich Town).
Toumani Diagouraga (Brentford) wins a free kick in the defensive half.
Foul by Tyrone Mings (Ipswich Town).
Corner, Brentford. Conceded by Tommy Smith.
Attempt blocked. Alex Pritchard (Brentford) right footed shot from the centre of the box is blocked. Assisted by Moses Odubajo.
Attempt blocked. Toumani Diagouraga (Brentford) right footed shot from outside the box is blocked.
Hand ball by Tyrone Mings (Ipswich Town).
Jonathan Douglas (Brentford) wins a free kick in the defensive half.
Foul by Jay Tabb (Ipswich Town).
Foul by Jonathan Douglas (Brentford).
Jay Tabb (Ipswich Town) wins a free kick in the defensive half.
Moses Odubajo (Brentford) is shown the yellow card for a bad foul.
Foul by Moses Odubajo (Brentford).
Jonathan Parr (Ipswich Town) wins a free kick on the left wing.
Jonathan Parr (Ipswich Town) is shown the yellow card for a bad foul.
Moses Odubajo (Brentford) wins a free kick in the defensive half.
Foul by Jonathan Parr (Ipswich Town).