Jack Leaning reaped the rewards of long hours working with Phil Jaques during the winter to score a career-best score and help Yorkshire establish their position during a hard-fought second day against Sussex.

The 20-year-old batsman from York spent the winter playing grade cricket in Australia with Jaques, Yorkshire's former overseas player, when they worked on his mental approach to the game.

Those intensive sessions paid off with an unbeaten 75, his second half-century in three matches, to help Yorkshire reach 208-3 by the end of the second day, still trailing Sussex by 108 runs.

On a slow wicket that was not conducive to scoring quickly, Leaning showed great composure in almost four hours at the crease and prevented Sussex making greater inroads, having been dismissed for 316 early in the day.

Arriving at the crease after lunch following Alex Lees' departure in the final over before the interval, he battled through a 9.3-over spell alongside Adam Lyth where Yorkshire added only 12 runs, with Australian seamer Steve Magoffin and off-spinner James Tredwell, on loan from Kent, operating in tandem.

But having battled through that early period, he survived unscathed after facing 215 balls, hitting eight fours, to ensure Yorkshire still had the opportunity to take control of the match if they are able to bat at a higher tempo on the third day.

"The other lads told me to keep switched on," said Leaning. "Sometimes it's hard to keep mentally strong when you're not scoring and you might get frustrated but you have to keep going, take no baggage into the next ball and face up to go again."

Yorkshire had begun the day brightly, restricting Sussex to just 16 more runs to their overnight 300-9 before Jon Lewis edged Jack Brooks to first slip and then Lees and Lyth forged a 56-run opening partnership.

But Magoffin, who finished with figures of 23-13-22-2, bowled with unerring accuracy throughout from the Park End and with little pace in the pitch, it was difficult for Yorkshire to accelerate as they would have liked.

Lyth hit Tredwell for two sixes over long off in an attempt to force the pace but after hitting 66, his fifth half-century of the season, an attempted pull off Magoffin flew to fine leg shortly before tea.

Andrew Gale, Yorkshire's captain, also fell attempting to be aggressive, bowled around his legs sweeping Tredwell, but Leaning and Jonny Bairstow combined in an unbroken 69-run stand spanning 27 overs.