MARK Stoneman was still going strong on a career-best 156 and Scott Borthwiock had contributed 105 to an unbroken stand of 204 when Durham reached tea on 286 for one.
Both of last season’s 1,000-run men timed the ball superbly on the placid pitch, taking full advantage of any width offered by the Middlesex seamers.
It took the introduction of young left-arm spinner Ravi Patel to apply any kind of brake as he bowled eight overs for 19 runs before Borthwick pulled him for four.
Stoneman reached his century off 105 balls shortly after lunch when he clipped Toby Roland-Jones off his legs for his 17th boundary.
Borthwick pulled the same bowler for the only six so far and hit 16 fours in his 132-ball hundred.
Stoneman was dropped on 116 by wicketkeeper John Simpson, diving across in front of first slip, off Tim Murtagh and there was a slightly sticky patch for both batsmen when Middlesex employed an all-spin attack.
Irishman Paul Stirling’s off breaks caused a few problems as between then the two batsmen survived three difficult chances to the two short legs.
Stoneman went ten overs without hitting a boundary as his third 50 occupied 88 balls. His previous best was the 131 he scored against Yorkshire in the last home match. The fact that the visitors scored 589 for eight in that game only adds to the mystery of why Middlesex chose to field on a sunny day.