Andrew McGlashan is a deputy editor at ESPNcricinfo
South Australia 8 for 510 dec (Head 223, Hunt 109) and 9 for 230 dec (Carey 82*, Nielsen 67) drew with Western Australia 5 for 409 dec (Green 168*, Bancroft 126) and 9 for 148 (Worrall 4-30, Grant 4-38)
Western Australia's No. 11 Liam O'Connor, who has yet to score a first-class run, survived the final over of a pulsating final day to secure a draw against South Australia.
Cameron Gannon, who had formed a 16-over stand with Cartwright when South Australia were pushing for victory in the final session, tried to farm the strike but struck the last ball of the penultimate over too well and collected a boundary.
However, O'Connor was able to negotiate six balls from Chadd Sayers although there was added agony for South Australia when the last delivery of the match lobbed in the air into the off side but didn't reach any of the close catchers swarming the batsmen.
South Australia's pace attack, led by the four-wicket hauls for Worrall and David Grant, put in a huge effort to try and secure the Redbacks' first victory of the season after they had declared shortly before lunch to leave a target of 332 in 75 overs.
Western Australia were never in a position to threaten the chase and the visitors sensed their chance when Grant, playing his first Sheffield Shield match in more than three years, had Cameron Bancroft caught at point and trapped Cameron Green lbw two balls later. Six overs later he added Josh Inglis and when Aaron Hardie edged Sayers, Western Australia were 5 for 88 with 45 overs still remaining.
Cartwright, batting at No. 7 after being off the field on the third day with a back problem, accompanied Shaun Marsh for 14 overs but Grant then made his next big impact when he found the edge of Marsh's bat, meaning the bowlers were exposed.
Matt Kelly played a poor stroke, splicing a pull off Worrall, to leave them seven down with 22 overs remaining before Cartwright and Gannon brought safety within sight deep into the final hour, but there was more drama to come.
Western Australia's last-wicket pair survive to earn gripping draw
Daniel Worrall and David Grant took four-wickets each but South Australia came up agonisingly short
Cameron Green hits 168 as Western Australia declaration opens up contest
The home side pulled out 101 behind then took early wickets before South Australia extended their lead to 243
Cameron Bancroft's hundred leads strong Western Australia response
Travis Head earlier completed his maiden first-class double century in a huge South Australia total