Sheringham brought West Ham level in the first minute of the second half with a coolly taken goal made by the cleverness of the Israel international Yossi Benayoun, who cost £2.5m from Racing Santander.
"We were nervous at the start but I felt at half-time that we could go on and win the game if we played with more confidence," said the West Ham manager, Alan Pardew. "That confidence came with Teddy's goal and we finished much the brighter team."
How often Sheringham appears this season (he was taken off after 72 minutes on Saturday) will be as much a matter for West Ham's backroom staff as the manager.
"I'll be guided by our sports scientist," Pardew said. "Obviously, Teddy is not going to play a full season. What we have to do is work out when to use him and when he needs a rest."
It could be that Sheringham will be used mostly against the Premiership's lesser clubs, particularly at Upton Park, where West Ham were given a rousing reception by a capacity crowd.
As Mark Hughes steered Blackburn well away from the threat of relegation last season, his uncompromising team earned a reputation for toughness that will see them appear before the Football Association today to explain their poor disciplinary record. It hardly improved their case when the serial offender Paul Dickov was sent off late in the game for a wild two-footed lunge at Paul Konchesky.
Hughes conceded that Dickov had got what he deserved. With a wry smile, he said: "We are trying to alter a perception of the way we play - hard but fair - so yes, if you raise both feet off the ground you are likely to get a red card. It was born a little of frustration because he [Dickov] felt, rightly in my view, we should have had two decisions just prior to that that the referee didn't give us. But that's no defence."
Hughes struggled to find an answer for the way his team lost impetus after dominating much of the first half and taking the lead through Andy Todd in the 18th minute, when West Ham failed to deal with a low corner from Morten Gamst Pederson. Blackburn's lead might have been greater but for Konchesky, who headed a Robbie Savage free-kick off the line with Roy Carroll clearly beaten.
"I don't think any of us saw what happened in the second half coming," Hughes said. "We've had a good pre-season, we've put in progressively better performances every game, so today we expected a continuation of that. At the moment we are scratching our heads."
One thing Hughes had worked out during play was the inability to close down Sheringham and the loss of too many tussles with West Ham's central midfielders Hayden Mullins and Nigel Reo-Coker. Pardew felt that Mullins had his best game for the club while Reo-Coker's driving runs awoke West Ham to the prospect of victory.
The West Ham manager was understandably delighted with his side's response in the second half.
"We needed to get back at them early and Teddy's goal did that for us. The crucial factor for us is to keep this coming in the Premier League, keep building. It's been a great day for West Ham and we should enjoy it. Then we move on."
Where they had probed for openings, West Ham raised the tempo, attacking along both flanks and getting midfielders quickly forward in support of Marlon Harewood. It was pacey, powerful stuff, all too much for Blackburn.
Much to Hughes' annoyance, heads began to drop and it came as no surprise when Reo-Coker took Matthew Etherington's short, square pass in the 62nd minute and fired a shot that gave Brad Friedel no chance.
Coming in the 80th minute, West Ham's third goal was the result of an error typical of Blackburn's second-half performance. They were under no threat until Brett Emerton gave the ball away to Benayoun. The Israeli kept his head, picking out Etherington for a tap in.
Goals: Todd (18) 0-1; Sheringham (46) 1-1; Reo-Coker (62) 2-1; Etherington (80) 3-1.
West Ham United (4-4-2): Carroll; Dailly, Ferdinand, Gabbidon, Konchesky; Benayoun, Mullins, (Noble, 84), Reo-Coker, Etherington; Sheringham (Newton, 72), Harewood. Substitutes not used: Hislop (gk), Ward, Zamora.
Blackburn Rovers (4-4-2): Freidel; Neill, Todd, Mokoena (Dickov, 72), Matteo; Emerton, Savage, Reid, Pederson; Kuqi (Gersko, 55), Bellamy. Substitutes not used: Enckelman (gk), Flitcroft, Tugay.
Referee: A Wiley (Staffordshire).
Booked: Blackburn Rovers Savage.
Sent off: Dickov (81).
Man of the match: Mullins.
Attendance: 33,305.Reuse content