Hampshire 281 for 6 (Ervine 103, McLaren 61, Leach 3-77) v Somerset
Ervine walked out to the middle when his side lost their first wicket in the fourth over of the morning. By the time he departed for 103 more than 80 overs later he had seen Hampshire to within sight of posting a competitive total.
McLaren helped add 112 for the fifth wicket. Jack Leach was the pick of the home attack with 3 for 77 off 30 overs while fellow left-arm spinner Roelof van der Merwe ended with 2 for 81 off 25.
Hampshire opted to bat first on a wicket with green tinges, a decision they might have doubted when Somerset opening bowler Lewis Gregory made an early breakthrough. Jimmy Adams played inside a good length ball with the score on 16.
Somerset introduced spin well before noon, with their leading wicket taker Leach and van der Merwe coming into the attack. The latter was rewarded with his fifth ball when he bowled Will Smith for 16 with a delivery that clipped leg stump.
James Vince, returning from England duty, did not resume the Hampshire captaincy - Will Smith continuing that role - and was bowled without scoring by Leach with a ball that pitched on leg, but took middle stump.
Van der Merwe claimed a second wicket just before lunch when he accounted for Adam Wheater, lbw playing back to a full ball, for 21, which made the total 92 for 4.
If the morning belonged to the home side then Hampshire spent the second session playing themselves back into the game.
Ervine, unbeaten on 39 at the break went to his half-century when he turned Gregory off his legs to square leg, his runs coming off 98 balls with five fours.
McLaren kept Ervine company and together the pair resisted the considerable pressure from the Somerset attack. McLaren went to his half-century with a boundary through the covers off Jim Allenby, having faced 139 balls.
The stand ended when McLaren was well caught by Tom Abell off the full face of the bat at short-leg off Leach, with the total on 210.
Ervine continued to move closer to his century, which he reached when he clipped Gregory behind square leg for two, his runs coming off 200 balls with 10 fours.
The new ball was only five overs old when Leach was brought back on and with his fourth delivery had Ervine leg before to end a fine innings.
Hampshire wicketkeeper Lewis McManus and Gareth Berg then remained together to see their side through to the close, by which time McManus was unbeaten on 41 and Berg was on 12.