Tony Pulis admitted he chose the wrong tactics as Preston held Middlesbrough to a 1-1 draw at Deepdale to leave Boro outside the automatic promotion spots.
The hosts should have been ahead before Alan Browne scored just before the break, giving Preston a slender lead at half-time.
Pulis' side hit back after the interval, substitute Marcus Tavernier levelling early in the second half as Boro drop down to third in the Sky Bet Championship.
"As the manager, you have to take the responsibility," commented Pulis. "The shape we started with, we didn't look comfortable with it.
"Whether that was the players in certain positions doing certain things for you or not, I don't know. But once we changed it, I thought we got much more into the game and were much more productive.
"We're pleased we got the point, but disappointed we didn't get all three with the opportunities we had in the second half, and the three clear-cut headers in the box that we should be making the goalkeeper save.
"Having said that, I can't be too critical of the players.
"Going to Brentford and then coming here, before the games had started, if you'd said we'd get four points, you'd bite people's hands off because that second game is always really, really difficult.
"They've won their last four games at home and this is the bounce game, it's the one that's really difficult."
Preston threatened as early as the second minute, but Lewis Wing blocked Brandon Barker's shot with an excellent covering tackle.
On the quarter-hour mark The Lilywhites' Jordan Storey teed up Tom Barkhuizen in the area but his shot clipped the post before Aden Flint cleared.
On 43 minutes a slick move culminated in Barker teeing up Browne – the midfielder firing a precise low finish into the corner.
One minute into the second half though Middlesbrough were level, Tavernier seizing onto Dael Fry's long ball to drill home as Boro drop down to third.
After the game, Preston boss Alex Neil commented: "We should have won the game. We had the chance that hit the post and is cleared off the line.
"Alan's goal is a great goal. Brandon (Barker) has a chance early on when he's clean through, Jordan Storey has a chance as well.
"We had more than enough of the game against a team second in the division. We were the better side, we showed more quality and posed them a lot of problems.
"Our lads don't stop, they're full of energy.
"We had two young kids playing in the middle of the back four against, I think they had nine lads above 6ft in their team. Our lads showed real character to match them.
"So to do what we've done over the last nine games and again tonight with six first team players missing, I think if you do that to any team, they'd do remarkably well to do as well as these lads have."
ga('create', 'UA-72310761-1', 'auto', {'name': 'pacontentapi'});
ga('pacontentapi.set', 'referrer', location.origin);
ga('pacontentapi.set', 'dimension1', 'By Press Association Sport Staff');
ga('pacontentapi.set', 'dimension2', '542c9230-b47b-4aff-af4f-71984cd3178f');
ga('pacontentapi.set', 'dimension3', 'paservice:sport,paservice:sport:club-news,paservice:sport:football,paservice:sport:match-reports');
ga('pacontentapi.set', 'dimension6', 'story');
ga('pacontentapi.set', 'dimension7', 'composite');
ga('pacontentapi.set', 'dimension8', null);
ga('pacontentapi.set', 'dimension9', 'sport:football');
ga('pacontentapi.send', 'pageview', { 'location': location.href, 'page': (location.pathname + location.search + location.hash), 'title': 'Pulis admits to tactical error as Boro are held at Preston'});
