Lozar, an 87th-minute replacement for Jonny Howson, side-footed home at the far post in a thrilling finale, two minutes after it appeared Vaughan – sent off for his goal celebration – had snatched all three points for Huddersfield with a goal in the sixth minute of added-time.
Norwich substitute Wes Hoolahan had earlier cancelled out Ishmael Miller’s opener for Huddersfield, but although the visitors remain unbeaten in the league on their travels since December 28, they still lost ground in the race for automatic promotion.
Six straight wins through February and earlier this month have propelled Alex Neil’s Norwich into contention for a top-two finish and an immediate return to the Premier League, but they came up against inconsistent Huddersfield on a good night.
Chris Powell’s side, who started the game nine points clear of the bottom three, deserved their point after a spirited performance but have still not beaten the men from Norfolk for 14 years.
Huddersfield were given an early let-off in the sixth minute when Norwich midfielder Bradley Johnson was adjudged to have handled before bundling the ball home from Cameron Jerome’s knockdown.
Amid Huddersfield’s furious protests, referee Nigel Miller consulted assistant Lisa Rashid and the goal was ruled out.
Visiting goalkeeper John Ruddy then did well to tip Joel Lynch’s thumping header over the crossbar following Jacob Butterfield’s corner as both sides looked intent on attack – Norwich the more cultured, Huddersfield more direct.
Huddersfield broke out for their best first-half moment in the 27th minute. Sean Scannell and Vaughan combined to set Conor Coady charging down the right and his brilliant cutback was blasted wide by Vaughan.
Town were now giving as good as they got, while Jerome could only slice his shot wide after bursting into the box following Johnson’s header.
Vaughan was denied by Norwich skipper Russell Martin’s last-ditch tackle after Miller’s through-ball, while Norwich striker Gary Hooper froze on the spot with the goal at his mercy just before half-time after Howson’s mazy run and cross.
Johnson crashed a shot wide for Norwich soon after the restart, but it was Huddersfield who carved out the opening goal in the 55th minute.
Butterfield clipped the ball into Miller on the edge of the area and the big striker deftly turned Martin and side-stepped into space before slamming home his second goal of the season 12 yards from goal.
Huddersfield’s lead did not last long though. Neil sent on Hoolahan for Johnson in the 62nd minute and five minutes later the midfielder steered home Hooper’s cross into the bottom corner for the equaliser.
There was no let up to the pace with the two sides going toe-to-toe for the winner and it seemed Vaughan had snatched it for Town when he converted Butterfield’s cross in the sixth minute of stoppage time.
But Norwich swept forward with the last play of the game and when Graham Dorrans’ shot rebounded to the far post, Lozar swept home an unlikely equaliser with the last meaningful kick of the game.