Bradley Hope finished unbeaten on 50.
Pakistan batsman Imam-ul-Haq went off the field for treatment after jarring his neck while fielding a ball during the morning session. Although the injury didn’t appear serious, he will be monitored ahead of the first Test at the Gabba, starting next Thursday.
The mercury soared past 40C on Saturday, and Pakistan made the hottest of starts to the day after declaring on their overnight score.
Jake Carder fell for an 18-ball duck when he chopped Abbas onto his stumps.
And Jayden Goodwin made just six before he edged Musa behind, leaving the home side in early strife.
But the prospect of Pakistan ripping through the rest of the CA XI line-up were thwarted by fighting efforts from Merlo and Spoors.
The brave display was in stark contrast to the powerful Australia A outfit, who got rolled by Pakistan for 122 at Optus Stadium earlier in the week.
That performance sent a powerful message to Australia about the talent of Pakistan’s pace attack.
But they haven’t been able to back it up with a glut of wickets against the CA XI.
Naseem Shah, a 16-year-old who has been likened to Dennis Lillee, unleashed some ferocious bouncers on Saturday but wasn’t able to snare a wicket during the first two sessions.
Abbas (2-22 from 14 overs) was excellent, while Musa (1-24 from 10 overs) was economical.
Imran Khan, who snared 5-32 against Australia A earlier in the week, and 19-year-old Shaheem Afridi are yet to bowl in the warm-up match, with Pakistan rotating through 15 players.
Asad Shafiq’s unbeaten 101 was the highlight of day one, with teenage spinner Lloyd Pope (5-100) also impressing.