Blackburn came from two goals drawn to snatch a vital point in the 2-2 home draw with local rivals Bolton. Rovers remain unbeaten under new boss Sam Allardyce who so very nearly lost that record to his old club.
But the South African international made amends with three minutes remaining, converting from close range.
"We're bitterly disappointed, we were two-nil up at half time and cruising, I can't remember a shot from the opposition," said Trotters boss Gary Megson.
"But the game changed when Roque Santa Cruz and Tugay came on. They had the momentum and we didn't deal with it, we ran out of steam.
Three of our last four games were against Arsenal, Liverpool and Man Utd and a lot of teams have still got to play them. One or two sides will implode, we have to make sure we're not one of them." Blackburn boss Sam Allardyce was pleased with the second half performance.
"It was a moral victory for us and on the second-half performance and chances we deserved to win it.
"We're undefeated in seven games and it's very important to go on from here. We showed character, commitment and desire in abundance.
"I thought the penalty was a straight red, Santa Roque Cruz was through on goal and he was hauled down, but Mike Dean deemed it to be a booking."