Hull recorded a second straight Premier League victory as a 2-0 win condemned Swansea to a first home defeat since February.
Shaun Maloney and Abel Hernandez struck in the final 12 minutes as the Tigers built on their surprise opening-day win over champions Leicester.
Maloney had only been on the pitch six minutes when Curtis Davies flicked on Robert Snodgrass’ 78th-minute corner and he finished from close range for only his second Hull goal.
Hernandez then wrapped up the three points in stoppage time as the Swans were punished on the break.
Swansea had also won their first game at Burnley, but they ran out of ideas at the Liberty Stadium after a promising opening when Modou Barrow’s pace had posed problems.
Until Maloney’s goal, it looked as if the main talking point would be referee Stuart Attwell turning down three genuine penalty claims in the first half – two from Swansea and one for Hull.
Barrow appeared to be taken out by Tigers defender Andrew Robertson after 14 minutes, even though the Swansea winger was running out of room in the area.
Five minutes later Leroy Fer fired at goal but Tom Huddlestone came in late and made contact with the Swansea midfielder after the ball had gone.
The hosts might have had cause to feel aggrieved that their claims were ignored on both occasions, but Hull seemed to have a more cast-iron case four minutes before the break.
Snodgrass’ run across the area was ended by Jordi Amat’s sliding tackle, but again Attwell waved play on even though the Spaniard appeared to make no contact with the ball.
Swansea’s new American owners Jason Levien and Stephen Kaplan were in attendance after completing their takeover of the club this summer.
They might have been celebrating a goal inside six minutes when Wayne Routledge laid Kyle Naughton’s cross into the path of Gylfi Sigurdsson.
The Iceland international made a sweet connection and the ball seemed destined for the top corner of Eldin Jakupovic’s net before the Tigers goalkeeper tipped it on to the crossbar.
That early chance set the tone for an open contest where Hull were content to sit and break at speed.
After Barrow’s penalty appeal was refused, Snodgrass set up Adama Diomande and the striker would have done better but for Amat’s last-gasp challenge which just did enough to put him off.
Barrow freed Routledge and his cross was met by Fernando Llorente, but the Spaniard failed to keep his header down and test Jakupovic from 10 yards.
Swansea were becoming increasingly frustrated in their struggle to create chances and it was showing in the theatrical response of their manager Franceso Guidolin in the technical area.
Davies, however, almost put the ball into his own net when Sigurdsson’s corner was allowed to travel across the six-yard box.
But the central defender soon left his mark in the Swansea area and Hull were on their way to making it six points out of six.