Bolton's victory over 10-man Middlesbrough - their eighth successive home win - ensured Dougie Freedman's side moved into the play-offs.
Bolton had numerous chances but had to wait for Chris Eagles to break the deadlock from 12 yards after the break.
Kieron Dyer converted Scott McDonald's cross from close range to level.
Parity lasted three minutes as Jonathan Woodgate was sent off for a foul on Marvin Sordell and the striker struck from the spot for a valuable win.
The victory ensured Bolton, without the injured Jay Spearing and David Ngog, leapfrogged Leicester into sixth place.
Bolton in top form
Bolton have won seven and drawn five against Middlesbrough since a 1-0 defeat in the old Third Division in April 1987.
The home team attacked from the kick-off, with Craig Davies's 18-yard effort in the second minute needing a fingertip save from Jason Steele.
Boro battled their way into the match and McDonald should have done better when presented with a chance from six yards in the 23rd minute.
Bolton looked the more likely to score, however, and they took the lead when Chung-Yong Lee released Eagles and the former Manchester United man struck for the 10th time this season.
The visitors soon levelled thanks to Dyer's header but Bolton quickly regained the lead with the help of Woodgate.
The defender felled Sordell and the striker made no mistake from the penalty spot, scoring his eighth goal of the season.
Bolton manager Dougie Freedman:
"It was a very good team performance. You've got to remember that we've played three very intense games in a week, so to hang on and dig in is what's getting us in the top six.
"The play-offs are in our own hands now, but it's still going to be difficult with us having to play Cardiff and then Blackpool.
"However it's a great thing to have at this stage of the season and we wouldn't want to have it any other way."
Middlesbrough manager Tony Mowbray:
"I thought we deserved more than that and we needed a better official to referee the game because there were some bewildering decisions out there today. The penalty was one of them and the sending-off was certainly one of them.
"Bolton started the game well, which they always do but I thought we had a decent foothold in the game and then they got a goal through a cross which just drifted in, but that's the way our luck has been going at the minute.
"I thought we were the better team but the history books will show that we lost. They won't show that we conceded a lucky goal and then a penalty, which having seen half a dozen times was never a penalty kick, but that sums up the referee's performance."
- 01 Bogdan
- 03 Alonso
- 12 Knight
- 15 Dawson
- 18 Ricketts
- 07 Eagles
- 21 Pratley
- 27 Lee
- 44 Medo
- 19 Sordell (Butterfield - 87' )
- 28 C Davies (Eaves - 72' )
- 24 Lonergan
- 05 Ream
- 43 Butterfield
- 25 Vela
- 41 Lester
- 17 Hall
- 32 Eaves
- 01 Steele
- 02 Hoyte
- 14 Williams
- 39 Woodgate Dismissed after an earlier booking
- 12 Dyer (Bailey - 69' )
- 16 McEachran (Emnes - 59' )
- 18 Halliday
- 33 Smallwood
- 08 Sa Ameobi (Bikey - 66' )
- 19 Carayol
- 27 McDonald
- 32 Leutwiler
- 03 Bikey
- 10 Bailey
- 38 Haroun
- 09 Emnes
- 23 Main
- 30 Miller