Aberdeen manager Derek McInnes rued his side's sloppy passing, poor defence and lack of ruthlessness in attack during their loss to Hearts.
The Dons surrendered second place in the Scottish Premiership with a 2-0 Tynecastle defeat.
McInnes was disappointed by his players' performance in the final fixture before the league split.
"We came here with high motivation and expectation to get a result," McInnes told BBC Scotland.
"We've got loads to play for and we played into Hearts' barrel.
"We were playing nothing football, just playing in around them without trying to get beyond them and hurt them."
Hearts capitalised on slack passing from the visitors to score through Steven Naismith then David Milinkovic in two first-half minutes.
"We were guilty of giving the ball away far too easily in poor areas," McInnes said. "Needless, poor decision making.
"At both goals, we had opportunities to clear it rather than allow them to pick it up. At this level, you can't concede such poor goals.
"We've hit the woodwork a couple of times and at least in the second half we offered some sort of semblance of trying to get into the Hearts box and cause them problems, but it was too few and far between."
Aberdeen's record against their top-six rivals is mixed, having beaten Hibernian and Kilmarnock twice apiece on league business this term.
Saturday's loss was their first of the season to Hearts, who sit sixth, but the Dons have failed to pick up a point against either half of the Old Firm, losing all six encounters.
McInnes' men tackle Motherwell in next Saturday's Scottish Cup semi-final at Hampden Park.
"Results against the Old Firm haven't been good enough," McInnes conceded. "What we're looking for is the bigger the game, the bigger the performance.
"When you lose a game, tactically or whatever, it's normally down to performance. We need to perform better against the Old Firm.
"But I'm confident we've got the players here, the motivation to do well."
'We have set high standards today'
Hearts manager Craig Levein challenged his team to keep their level of performance high in the post-split fixtures.
"We wanted to try and win the game, we wanted to go home and send the supporters home happy," he told BBC Scotland.
"We're very good here. The challenge for us is to be just as good away from home.
"The shape of the team was excellent and we never really allowed them to create the gaps that would've caused us problems.
"We stayed compact and moved together all over the field and that made it really difficult for them to play through us.
"So they ended up playing a lot of long balls and we coped with those admirably.
"Today I felt we were more comfortable in possession. The pitch here is getting better and we passed the ball and were brave in possession.
"We have set high standards today and hopefully we can reach those for the rest of the season."