Williams has had one game since post-British and Irish Lions tour shoulder surgery - for Cardiff Blues against Ospreys - but is expected to take on fellow world-class openside Richie McCaw at the Millennium Stadium on Saturday.
First Tagicakibau danced around two defenders for his first try just minutes after coming off the bench and then Stowers slammed the ball into the base of the post to score his as Irish appeared to kill off the contest and threatened to run riot.
On Wednesday evening, Ireland team manager Roy Torrens said the issue was a "misunderstanding" and that the Irish Cricket Union's cheques to the players "are in the post".
On a showery day by the coast, Irish skipper Trent Johnston won the toss and smashed three late sixes in his 52 to post a total of 221-6 from 48 overs.
The Swans defence held off striker Keogh's rampaging run but the Irish international fed Peter Whittingham whose 25-yard left-footer just whistled past de Vries' left-hand post.