Reda Johnson scored the only goal as Sheffield Wednesday beat Leyton Orient to move into second in League One.
The Owls nearly went ahead but only a last-ditch interception from Orient's Scott Cuthbert denied Michail Antonio.
Johnson scored when he reacted first to stab the ball home after O's goalkeeper Paul Rachubka had parried his earlier header from a Chris Lines free-kick.
The hosts almost snatched a point in injury-time but substitute George Porter's volley went narrowly wide.
Wednesday are now one point ahead of third-placed Sheffield United, although the Blades have a game in hand.
Orient, who have lost four of their last five matches, are four points clear of the relegation zone.
VIEWS FROM THE DRESSING ROOM
Leyton Orient manager Russell Slade told BBC London 94.9:
"They're a good side and are going to create chances. They're a big side with a big budget and a big playing staff so it was always going to be a tough game against them.
"But for us to be in the game 0-0 at half-time, then that's ok for us.
"We stayed in the game and I'm disappointed to concede after half-time. We didn't cause them too many problems but nearly got something at the death."
Sheffield Wednesday manager Dave Jones tells BBC Radio Sheffield:
"After Tuesday's match we needed to bounce back and the side (Leyton Orient) put out was an attacking one.
"We certainly had a lot of chances today and we could have made life a lot easier for ourselves.
"While it was only 1-0 they were hanging in there with (the threat of) a set play.
"I thought we should have done a lot better with the situations we were in and we cold have made it two or three."
Leyton Orient 28 Rachubka 04 Chorley 05 Cuthbert 06 Forbes 14 McSweeney 07 Cox 08 Reed (Porter - 66' ) 20 Smith 26 Leacock (Laird - 79' ) 09 Lisbie 29 Campbell-Ryce (Andrew - 87' ) Substitutes 02 Ben Youssef 15 Porter 17 Laird 11 Andrew 39 Mooney Sheffield Wednesday 43 Bywater 02 Buxton 05 R Jones 17 R Johnson Booked 32 Llera 06 Semedo 08 Lines 11 J Johnson (Treacy - 78' ) 27 Antonio 09 O'Grady (Ranger - 61' ) 14 Madine (Lowe - 87' ) Substitutes 24 Jameson 13 Beevers 10 Treacy 30 Lowe 31 Ranger