Robert Earnshaw tasted the highs and lows of life as a striker as Cardiff City sealed a third win in a row which keeps them on the fringe of the first division play-offs.
Earnshaw netted the winner for Wales in the 2-1 victory over Hungary in midweek but missed a penalty, on his way to scoring his 26th goal of the season.
He said: "It's been a great week for me and I hope it continues. The game at Millwall is massive and we have just got to go again there and hope that we can keep our good form going." Earnshaw spurned his chance from the spot after 18 minutes. Leon Johnson was adjudged to have pulled back Alan Lee in the box and Suffolk referee Michael Thorpe pointed to the spot.
However, Earnshaw could only watch as Gillingham keeper Steve Banks dived to his left to keep out the effort and keep the hosts in the game.
Earnshaw netted four when Cardiff hammered the Gills 5-0 at Ninian Park earlier in the season, and he was on target again nine minutes before half time.
Banks lost a 50-50 race to the ball with Paul Parry whose precise left-wing cross was glanced in by Earnshaw.
He and John Robinson went close in first-half stoppage time to increasing Cardiff's lead, but the second half proved a far different story.
Gillingham, who had Alan Pouton and Nicky Southall booked, also saw player-manager Andy Hessenthaler booked in the tunnel by Mr Thorpe after the two exchanged words as the players left the pitch.
Hessenthaler and assistant Wayne Jones rallied the home side and they went out and had their best spell of the game.
Cardiff had to replace the injured Daniel Gabbidon soon after the break and then Gillingham got back on level terms when Chris Hope headed in Nicky Southall's corner.
New boy Gary Wales, making his full debut, also did well and was inches away from giving Gillingham the lead.
Lennie Lawrence then sent on loan substitute Lee Bullock and he headed in the winner four minutes from time.
However, there was still a sting in the tail as Cardiff skipper Tony Vidmar brought down Wales in the box, only for Pouton to blaze the spot kick wide as Gillingham's misery from the spot continues. This was their fourth miss from eight attempts this season.