|Cardiff Blues (10) 20|
|Tries: Vosawai, James Cons: Patchell (2) Pens: Patchell (2)|
|Connacht (13) 16|
|Tries: Porter, McKeon Pens: Porter, Carty|
Struggling Cardiff Blues shocked Pro12 leaders Connacht to claim only their second league win of the season at the Arms Park.
Number eight Manoa Vosawai and wing Tom James scored tries, with Rhys Patchell kicking 10 points.
A much-changed Connacht side led 13-10 at half-time after tries by scrum-half Ian Porter and back-rower Eoin McKeon.
Blues hit back after the break and held out to inflict a second defeat of the season on Connacht.
It was Connacht's first defeat in seven Pro12 matches, and the Blues' first win in seven.
The difference between the form of the teams could not have been greater at the start of play.
Connacht, fresh from an historic away win over Munster, had lost only once this season and were 22 points ahead in the table of the Blues, whose only Pro12 win came against Zebre in the first week of September.
Showing eight changes from the win at Munster, Connacht were led onto the field by John Muldoon, who became the first player to make 200 appearances in the Pro12.
But it was the Blues who started the brightest and, after opting for an attacking lineout, drove over with Italy's Vosawai claiming the try.
But their good early work was undone by a series of handling errors that handed momentum to Connacht.
The Irish province took full advantage when the influential Porter rounded off a sweet handling move by diving over in the left-hand corner.
The visitors dominated the rest of the half, with McKeon touching down from a rapidly advancing line-out drive and Porter kicking a penalty after twice hitting a post with conversions.
Connacht were severely disrupted by injuries to second row Quinn Roux and scrum-half Porter near the end of the opening half.
And within seconds of the re-start, Porter's replacement Kieran Marmion suffered a blow to the head tackling Alex Cuthbert and had to leave the field, with left wing Matt Healey filling in at number nine for the rest of the game.
With a strong wind behind them, Blues dominated territory and, after Patchell missed a straight penalty, opted to kick for the corner when the Irish team were next penalised.
It paid off when James stretched to claim his try, with Patchell converting and then kicking a penalty from halfway as the Blues opened up a seven-point lead.
Fly-half Jack Carty brought Connacht back to within four points and Blues survived a couple of scares, most notably when centre Bundee Aki carved a huge hole in the home defence.
Danny Wilson's team repelled a couple of driving line-outs in the closing minutes to claim a morale-boosting win.
Cardiff Blues: Rhys Patchell; Alex Cuthbert, Ray Lee-Lo, Gavin Evans, Tom James; Jarrod Evans, Lloyd Williams; Gethin Jenkins (capt), Ethan Lewis, Taufa'ao Filise, Jarrod Hoeata, Lou Reed, Macauley Cook, Josh Turnbull, Manoa Vosawai.
Replacements: Kristian Dacey, Sam Hobbs, Craig Mitchell, James Down, Cam Dolan, Tavis Knoyle, Garyn Smith, Dan Fish.
Connacht: Tiernan O'Halloran; Darragh Leader, Bundee Aki, Craig Ronaldson, Matt Healy; Jack Carty, Ian Porter; Ronan Loughney, Dave Heffernan, Rodney Ah You; Quinn Roux, Aly Muldowney; John Muldoon (capt), James Connolly, Eoin McKeon.
Replacements: Jason Harris-Wright, Conan O'Donnell, Finlay Bealham, George Naoupu, Sean O'Brien, Kieran Marmion, Peter Robb, Rory Parata.
Referee: Andrew Brace (IRFU)
Assistant referees: Neil Hennessy, Simon Rees (WRU)
Citing commissioner: Gwyn Bowden (WRU)
TMO: Jonathan Mason (WRU)