Dave Rennie felt Chiefs were "pretty average" in the Super Rugby leaders' hard-fought 24-22 win over Sharks at Yarrow Stadium on Friday.
Rennie this week made his anger known after allegations of cheating were levelled at his side following their 28-27 win over Hurricanes and he was still far from happy despite watching Chiefs make it eight wins out of nine.
Sharks outscored the leaders by three tries to two, but fly-half Aaron Cruden scored 14 points with the boot as Chiefs edged a tight contest.
"We were pretty average tonight," he said. "It was a pretty flat performance. We knew they would kick a lot and we wanted to win that battle and have a crack off the second kick, but we just kicked poorly and didn't look after the ball well enough.
"When we did we put them under pressure we stuttered our way through it and we were lucky to get a result."
Adriaan Strauss and Jan Serfontein scored two tries apiece as Bulls extended their winning run to five matches with a 42-20 victory at a Western Force side who have now lost seven in a row.
Chiefs 24-22 Sharks
Sharks were caught cold when Seta Tamanivalu broke from midfield to score the opening try in the first minute and were really up against it when Michael Leitch went over to make it 15-3.
But the Durban side proved to be more than a match for the leaders and were level at half-time following a Kyle Cooper try and a brilliant individual effort from Garth April.
The interval halted Sharks' momentum and three Cruden penalties made it advantage Chiefs once again, ensuring a late Chiliboy Ralepelle score was too little, too late.
Western Force 20-42 Bulls
Hanro Liebenberg marked his first start at number eight this year by going over for the opening try and Serfontein rounded off a fine team try before Matt Hodgson went over in the corner as Bulls lead 18-13 at the break.
In-form Bulls turned the screw in the second half after Brynard Stander was sent to the sin-bin, with Serfontein spinning out of a tackle to touch down again and Strauss also helping himself to a double.
THE KEY MOMENTS
Sharks had the bit between their teeth following a strong finish to the first half, but Cruden - who landed five out of seven kicks - restored their lead from the tee after Cooper was penalised for offside and another two penalties from the New Zealand fly-half ensured the tide had turned back in Chiefs' favour.
Western Force put Bulls on the back foot at the start of the second half, but were unable to find a way through and the visitors took advantage by putting the game to bed in Perth.
Sharks captain Keegan Daniel: "When we look at the tape, our discipline probably let us down a bit. We let them off the hook at crucial times. We've come away with six points from this tour so we'll look back and say, 'We'll take six,' and regroup when we get back home."
Bulls centre Jesse Kriel told Fox Sports: "The guys had a lot of fun and scored some nice tries. We attacked quite well and it was a good performance. The new coach [Nollis Marais] has brought in a new attacking mindset and the guys are really enjoying it."
Chiefs are guaranteed to be top of the standings at the end of round 10 as they lead Crusaders by five points and Todd Blackadder's men have a bye, while Sharks are fourth in the South African Group and five points adrift of Africa 2 leaders Lions.
Bulls are level on 28 points with Stormers at the top of the South African Group and Africa 1, with Western Force rooted to the bottom of the Australasian Group.