Middlesex failed to build on an excellent start from openers Nick Compton and Sam Robson, finishing the second day of their LV County Championship Division Two encounter with Northamptonshire at Lord's on 310 for six.

Compton (82) and Robson (75) posted 167 before being parted, having shared the county's highest first-wicket stand of the season and taken just 72 minutes to take the total into three figures.

But the middle order could not match them as Middlesex finished the day with a lead of just 22.

Compton was particularly aggressive to deliveries on or wide of the off stump and needed just 46 balls to reach his half-century, which included nine boundaries as he outscored his 20-year-old partner by two to one before lunch, at which point they had made 118 in 25 overs.

The afternoon session saw Robson move into top gear as he completed an 85-ball maiden championship half-century in an innings of selective drives and pulls all cleanly hit as both batsmen timed the ball sweetly to dominate proceedings.

However, both fell in the space of three overs when the attractive stand was finally broken by David Wigley, who had Compton picked up by Nicky Boje at cover.

Fourteen runs later, Johannes van der Wath then found the thinnest of outside edges to have Robson caught behind by Riki Wessels.

Owais Shah struck four boundaries in a rapid 24 before Northamptonshire's leading wicket-taker David Lucas squeezed a ball between bat and pad to knock back off stump.

Dawid Malan (10) fell to an indeterminate prod forward to a ball from slow left-armer Boje and was caught at forward short leg to leave the home side 213 for four.

Eion Morgan, who had passed 50 only once this season in the competition, batted confidently and launched his innings with a superb straight drive off Van der Wath on his way to a 76-ball half-century.

He continued to play with authority during an 85-runs alliance with Ben Scott that included a robustly hit straight six by the Dublin-born batsman off Boje before Scott was yorked for 20 by the persevering Van der Wath.

Morgan, having reached a stylish 71, was leg before when he stabbed forward to Boje, but four balls later rain forced the players from the field with 20.2 overs of scheduled play still remaining.

Tim Murtagh had needed just five deliveries at the start of the day to take the remaining Northamptonshire wicket, trapping David Lucas in the crease for a duck to finish with three for 63 as the visitors failed to add to their overnight score of 288.