Gary Keedy returned his best figures since August 2010 as Surrey had the better of day four in their LV= County Championship draw with Yorkshire at Headingley.
The veteran left-arm spinner, who moved from Lancashire in the winter, more than doubled his previous tally of wickets for Surrey as Yorkshire slipped to a second-innings 160 for six during the early stages of the afternoon session. At that stage the White Rose had a lead of 240 with the best part of 64 overs left in the day.
They were 182 for seven shortly afterwards but the lower order, including Steven Patterson batting with a cracked left big toe, resisted.
Liam Plunkett's 68 off 138 balls, his second half-century of the match, was crucial in Yorkshire's score of 254 all out as Keedy took 7-99 from 39.1 overs.
It means the White Rose are currently top of Division One after nine matches but they may not head into the break for the Friends Life t20 in that position because Sussex would leapfrog them with victory over Nottinghamshire. Yorkshire claimed eight points and Surrey, who climbed out of the relegation zone, nine.
Keedy, who started his career with his native Yorkshire, had only taken four championship wickets for Surrey heading into the second innings.
His first scalp of this haul came during the latter stages of day three when he trapped Alex Lees lbw.
Yorkshire resumed this morning on 52 for one with a 132-run lead - and they had made their way to 76 by the time Adam Lyth played on for 32 as he attempted to sweep Keedy.
Keedy then had Andrew Gale caught at square-leg on the sweep and debutant Jack Leaning, replacing England Twenty20 new boy Gary Ballance, caught at slip, both for ducks in the space of three balls.
And when Joe Sayers miscued a pull at Chris Tremlett to Keedy at point in the 41st over, Yorkshire were 114 for five.
Adil Rashid dominated a sixth-wicket stand of 46 with Andrew Hodd, finishing with 45. But he was bowled by Keedy early in the afternoon session.
Hodd was later trapped lbw by Tim Linley before Ryan Sidebottom edged Keedy to slip, leaving Yorkshire 209 for eight in the 74th, by which time a draw was a near certainty.
After 51 in the first innings, Plunkett reached his second fifty off 105 deliveries with the second ball after tea. Patterson scored seven off 45 balls in a stand of 39 inside 18 overs before offering a return catch to Linley.
Keedy's seventh scalp was that of Plunkett, stumped, before Surrey, faced with an irrelevant target of 335 in 21 overs, reached four without loss prior to the players shaking hands at 4:55pm.