And there were two goals for Kiko Seike in the 3-0 success over Southampton.
Albion saw off their dogged opponents from the Championship to move to six points from three games in their League Cup group.
Defeat at West Ham still looks like costing the Seagulls a place in the last eight.
But they can do their bit by beating Charlton in their final group game while hoping the Hammers suffer a slip-up.
Kirby’s goal on 71 minutes was a clever little chip over the keeper’s dive, similar to that by Welbeck against Newcastle the previous afternoon.
She was picked out by a precise through ball from Jorelyn Carabali, who spotted Kirby’s clever run in behind the defence.
Kirby took her time and applied the expert finish.
That came just three minutes after Seike had opened the scoring.
Rachel McLauchlan’s flick worked a bit of room and Seike found the top corner.
Seike later tapped in from close range after a low cross caused problems.
Albion were unable to make a first-half breakthrough.
Michelle Agyemang fired a low shot against the post and Rosa Kafaji whisked a half-volley wide after being picked out by a superb cross from Carla Camacho.
Marit Auee scooped a shot over in the second half and Marisa Olislagers was denied by a good save.
Albion now go into an international break before returning with a major test at home to Manchester United, who visit the Broadfield Stadium on Sunday, November 2 (midday).
Albion: Baggaley, McLauchlan (Hayes 81), Auee, Carabali, Olislagers (Martin 81); Tsunoda, Kirby (Gay 87), Noordam; Camacho (Seike 63), Agyemang, Kafaji (Minami 63). Subs not used: Nnadozie, Rule, Symonds, Heron.