The hosts recovered from an early 10-point deficit to lead 12-10 at half-time, with tries from Mack Hansen and Josh Ioane.
Connacht have opened their United Rugby Championship campaign with a 29-15 defeat to the Stormers in Galway.
The hosts recovered from an early 10-point deficit to lead 12-10 at half-time, with tries from Mack Hansen and Josh Ioane.
A Sam Gilbert penalty stretched Connacht's advantage to five points after the break, but the game shifted when Paul Boyle was sent to the sin-bin.
The Stormers took control from there, with Sazi Sandi crossing before late tries from Vernon Paulo and Ezekiel Ngobeni secured the bonus-point victory.
Connacht were still within two points heading into the closing stages, but the South African side finished strongly to pull clear.

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