Middlesex on top at Lord's
Watch highlights of day three
Middlesex were closing in on a maiden LV= County Championship Division One victory of the season after controlling the third day's play against Nottinghamshire.
Sam Robson added 19 to his overnight total for a score of 163, including 22 fours.
Having seen the opening batsman dominate the Notts attack until he fell to Andy Carter, Middlesex profited from 108 by wicketkeeper John Simpson that secured a first-innings lead of 113.
Simpson finished unbeaten in a score highlighted by 17 fours and one six before Steven Finn took three wickets to hamper Notts' response.
A final-session fightback from Riki Wessels and Chris Read, who finished unbeaten on 20 and 43 respectively, helped the visitors to 184 for five at the close of play, establishing a lead of 71 that offers hope for day four.
Even with Gareth Berg unable to bat, Middlesex amassed 439 from their first innings.
Berg missed the day's play after waking up with his arm in considerable pain and the South African-born all-rounder was sent to hospital for an X-ray and scan.
2nd Middlesex centurion @JohnSimpson_88 raises his bat - he finished the innings 108* #Middlesex150 pic.twitter.com/UXXpEPHRqx — Middlesex Cricket (@Middlesex_CCC) April 15, 2014
The results and level of Berg's discomfort will dictate whether he plays any part in the final day of the season's opening fixture at Lord's.
Once opener Steven Mullaney had been removed by Tim Murtagh for 11 in only the third over, Notts began making small inroads into their opponents' lead.
A flurry of boundaries from Phil Jaques and Michael Lumb got the scoreboard moving in front of a small scattering of spectators mainly confined to the Grand Stand.
But when Jaques fell lbw to Finn and Lumb joined him in the pavilion shortly after tea having compiled an admirable 37 - Murtagh did the damage this time - their momentum was gone.
Just as they appeared to be building up a head of steam with Samit Patel hitting three boundaries, Finn struck again with an lbw decision that reduced them to 105 for four.
James Taylor now led the resistance but he fell on 33 as the succession of lbws continued unchecked with Finn trapping the middle-order batsman in front.
Stability was finally provided by Wessels and Read, who put on 64 with the skipper making quick runs in the last half-hour, and their alliance will be vital if their side are to deny the hosts victory.