Pakistan 357 for 7 (Shafiq 135*, Sohail 79, Keogh 3-83) lead Northamptonshire 259 (Rossington 90, Shadab 6-77) by 98 runs

Asad Shafiq keeps an eye on the movement of the ball Getty Images

After so little first-class cricket in the past 12 months, batting practice is what Pakistan are most in need of before the opening Test of their UK tour that begins on Friday. They were handed a perfect chance on a golden second day in Northampton and Asad Shafiq took advantage of the conditions - as well as two dropped catches - to make his 20th first-class century and hand his side a sizeable lead by the close.

Shafiq has not only the second-highest number of Test caps in the Pakistan squad but has played more first-class cricket than most of the touring party in recent months. By complete contrast, before last week's match at Kent, Haris Sohail's last domestic first-class match was all the way back in 2014. The pair shared a stand of 136 for the third wicket to set the day up for their side.

As preparation for the Test matches to come, this has been a true assignment for the tourists and they were kept in check for two-thirds of the day. Northamptonshire took two early wickets and had Shafiq been held by Ricardo Vasconcelos in the gully on just 13 - a sitter straight to the fielder at chest height - Pakistan would have been 70 for 3 and three of their top order left with successive failures to begin the tour.

But the partnership steadily built either side of lunch. Sohail, despite - or perhaps because of - his recent experience being almost exclusively against the white ball, was initially the more fluent of the pair. He began with a back-foot punch and a front-foot drive through extra cover before skipping down to Rob Keogh's offspin to lift another boundary over mid-off. And after being struck a nasty blow on the neck ducking a Gareth Wade short ball that didn't get up, he went through to fifty in 107 balls with seven fours.

A century loomed for Sohail but he produced a leading edge to point trying to flick Keogh over midwicket against the spin. Steven Crook took a smart diving catch and should have taken Shafiq's top-edged sweep diving in the opposite direction next ball. But the second chance Shafiq offered went down and he was left to dominate the day.

Shafiq made 363 runs at 30 in Pakistan's Quaid-e-Azam Trophy last season without a century but here took his chance to reach three figures. He slog-swept his second six off Keogh before clipping the same bowler to long-on to raise fifty in 98 balls. A steer behind point moved Pakistan into the lead shortly after tea before a fine sweep brought up his century, Pakistan's first of the tour.

Later, just when Northants had ambitions to limit the deficit after three wickets with the second new ball, Shafiq took three boundaries in an over off Wade with a leg glance, a fierce pull and an uppercut over cover.

But the innings of the day belonged to Babar Azam, who breathed life into a sleepy afternoon with a bright, punchy 57. Azam already has seven ODI centuries and could become one of world batting's stars. Three of his first four scoring strokes were boundaries and as he cut Luke Procter wide of third man to raise fifty in just 61 balls with six fours, the day began to drift from Northants. One hundred and forty three runs came in 33 overs after tea as the lead approached three figures and Pakistan achieved the solid batting day they had hoped for.

It did not appear that would necessarily be the case as both opening batsman failed. Imam-ul-Haq, having scratched around for 60 deliveries for only 11 runs, was beaten on the inside edge by Keogh to be trapped lbw and Azhar Ali, the most experienced member of the Pakistan squad, fell lbw to Wade. The wicket was just Wade's second in first-class matches, having missed the majority of last season with a stress fracture of the back. He said he enjoyed the challenge of bowling to a high-class batting line up but it was a challenge successfully met by Shafiq, Sohail and Babar.