Middlesex 349 (Gubbins 75, Scott 55, Lace 51, Abbas 4-72) and 223 (Simpson 59*) drew with Leicestershire 268 (Ackermann 63, Dearden 61, Rayner 4-58) and 226 for 5 (Ackermann 70*)
Leicestershire's hopes of a first County Championship win at Lord's for 39 years were thwarted by rain as their see-saw clash with Middlesex ended in a draw.
The pendulum had appeared to swing back in the visitors' favour, with Colin Ackermann unbeaten on 70 from 88 balls, and five wickets standing as they chased a victory target of 305. But the overcast conditions, which led to five separate stoppages during the final day, eventually triumphed as the match was abandoned with the Foxes on 226 for 5 - still 79 short.
Middlesex, who have yet to record a Championship win this season, dropped three catches, but were still scenting an opportunity after removing the visitors' top four, all to lbw decisions, with 154 on the board.
Leicestershire began the fourth day on 38 without loss, needing another 267, but they had shaved only three more off that target when the darkening St John's Wood sky brought about the first of the weather delays.
With the Lord's floodlights switched on and the players back on the field, Leicestershire extended their opening stand to 51 before James Harris made the breakthrough, trapping Ateeq Javid in front of his stumps.
One other wicket fell during the morning session, with the consistent Ethan Bamber removing Paul Horton - but Middlesex should have claimed at least a third before lunch. Hasan Azad, who made a slow start to his innings, was the fortunate recipient of two reprieves with just seven runs to his name.
First, Sam Robson spilled an edge at first slip off the bowling of Harris and, in the next over, when Azad drove Ollie Rayner, Nick Gubbins was unable to pocket the chance at short cover.
That double escape appeared to help Azad lift the shackles and he and Mark Cosgrove, with a breezy 22 from 42 balls, guided the Leicestershire total past 100.
Rayner removed Cosgrove in the third over after lunch, but Ackermann immediately displayed an attacking intent, using his feet to the off-spinner and climbing into Harris as he struck successive boundaries. The South African dominated a fourth-wicket partnership of exactly 50 with Azad, contributing 34 before Harris registered his second lbw of the innings to dismiss the latter.
Harry Dearden, who had shared a century partnership with Ackermann on the second day, survived an early scare when he miscued Rayner to mid-off, but the chance eluded the diving Bamber.
Despite a further half-hour's delay due to rain, the fifth-wicket pair added another 52 before Tom Helm uprooted the off stump of Dearden. Ackermann did his best to maintain the Leicestershire charge in tandem with Lewis Hill, but a further downpour finally put paid to the visitors' hopes of forcing a victory.