Captain Jonathan Trott struck a heartening unbeaten half-century as England Lions had to settle for a draw against a Gauteng Invitation XI to start their tour of South Africa.

Trott (79 not out) missed out in the Lions' first-innings 443 all out but, in just his second attempt back in England colours since the stress-related issues which afflicted him in the 2013 Brisbane Ashes Test, he made no mistake.

He and Lions debutant Sam Billings (53) were to the fore in a century stand as the tourists augmented their lead early on a glorious final morning, before an afternoon declaration on 176 for five in Soweto.

Trott left his bowlers a scheduled 56 overs to see off their inexperienced hosts, and the Lions were on track until an approaching electrical storm brought a tactical retreat and early close after Gauteng had stumbled to 120 for eight in 42.

The captain counted five fours and a six, flicked over midwicket off seamer Nono Pongolo, in his 84-ball half-century - and Billings, given his chance despite not initially featuring in the batting XI for this non first-class fixture, upped the ante to hit seven boundaries from 67 deliveries in his 50.

The tourists batted on after lunch, with Billings retiring out. Set a purely notional 441 to win, the hosts were then soon in trouble again as the Lions' five-strong seam attack followed up first-innings gains.

Jonny Bairstow's athleticism behind the stumps gave his Yorkshire team-mate Jack Brooks the first success, a catch down the leg-side accounting for Yassar Cook.

Wickets were evenly shared as Boyd Rankin beat opener Karabo Mogotsi for pace and Mark Wood found Yaseen Valli's outside-edge for another Bairstow catch.

Surrey seamer Matthew Dunn struck straight after tea, bowling Wesley Landsdale, before Yorkshire pair Liam Plunkett and Adil Rashid got in on the act.

Craig Overton was drafted in to become the Lions' sixth seamer, but it was off-spinner Adam Riley who teamed up with Alex Lees - with a one-handed catch at midwicket - for a party-piece success as he struck with his first delivery for the eighth wicket.

Gauteng appeared to be collapsing to defeat until the weather intervened.