Pressure serving from new boy Pascal Cottet gave Riga a first set lead before Malory took control and triumphed 15-9 despite fine play from skipper Tom Young, Cottet and John Gilling.
In the second set Warwick found difficulty converting possession and despite quality contributions from setter Phil Wyles and Ben Bunn went down 15-6.
In going down 15-7 in the third set they did not disgrace themselves. Indeed they came back strongly in the latter part, having lost their way and confidence in the middle of the set.
Riga captain Tom Young said: "We knew we were unlikely to win but we wanted to play well and we did. In fact Malory complimented us on how well we played."
