Dean Elgar kicked off the first leg of his farewell tour with the 78th century of a run-infused career to help Essex into a commanding position in the relegation dogfight against Surrey.

The 39-year-old former South Africa captain announced his retirement on the eve of his 280th first-class appearance and made sure he would not bow out with a whimper when he departs the game at the end of the season. En route to a characteristically pugnacious 191-ball 113, Elgar passed 19,000 career red-ball runs.

However, the Indian legspinner Rahul Chahar prevented Essex establishing a lead greater than 96 by taking 6 for 80, the ninth five-wicket haul of his career, as the last seven wickets fell for 61 runs to leave Essex a slightly disappointing 279 all out. But that disappointment was soon forgotten as Surrey’s top order subsided and they closed on a parlous 51 for 4, still 45 behind.

By his own standards Elgar has not enjoyed the best of seasons with the bat but here he went past fifty for only the fourth time – three of them versus Surrey. So far, he has scored 212 of his 550 Rothesay County Championship runs against his former county.

But this was a different Elgar. Gone was the twitchy, jumpy left-hander who had been peppered the previous evening by Dan Worrall in fading light. Instead, as the pitch flattened out from its capricious nature on day one, Elgar showed some of the classic touches of his 20-year professional career, even quietening Worrall with a short-arm pull for a low, fizzing six.

Tom Westley also looked more relaxed the morning after the battering of the night before and had put on 47 for the second wicket before he was given out lbw, after a long think, to a Worrall delivery that might just have clipped leg stump.

Charlie Allison was slightly less expansive than his senior partner, but brightened when driving Tom Lawes through the covers for four, then pulling a six over midwicket next ball. But after a partnership that occupied 29 overs and was worth 111 runs, Allison fell to a chest-high catch at second slip for Chahar’s first scalp.

Elgar reached fifty with his seventh four, guiding Matt Fisher to third man, and passed three figures with his 12th, dispatching the equivalent of a spinner’s rank long hop from Chahar through midwicket. In attempting something similar to Surrey’s other spinner Mahipal Lomror, however, he dollied up a catch to short midwicket after a four-and-a-quarter-hour innings that included 14 fours and that six.

That precipitated the major collapse from 218 for 3 inside 19 overs either side of tea. Matt Critchley followed six balls after Elgar’s exit, tucked up by Lawes before Chahar took centre stage. Michael Pepper was first to go, nicking to slip. Two balls later Zaman Akhter drove uppishly to wide mid-on. And after the interval Simon Harmer cut to point, Jamie Porter edged behind and Sam Cook was bowled.

Harmer then snapped up two quick wickets in Surrey’s second innings, having Dom Sibley pushing the ball into the hands of short leg and Rory Burns lbw attempting a sweep. To compound Surrey’s woes, Ollie Pope got a leading edge to give Cook a return catch. And to the last ball of the day, Fisher fell in the slip cordon to Snater.

For much of the last decade, Essex and Surrey have challenged at the top end of the Championship, winning six titles between them. Both have suffered blips of late and are now more concerned with affairs at the wrong end of the table, but knowing that a late surge during the run-in could elevate them in what is a tight league.