The Brazilian centre-back was dismissed on the hour after checking Joe Tillen's run on goal. The contact looked minimal but Chelsea would argue Defendi was the last man and referee Mr Vaughan did not hesitate to show the red card.
With that in mind, it was a good point against a team just one place below us in the Barclays Premier League South but the sending off came just as we looked like we might get our noses in front.
We were just about the better side in a disjointed first half, lifted by some wonderful crossfield passing from Sean Davis, but we got a grip of the game after the break and forced home keeper Lenny Pidgeley into four decent saves, including a double stop to deny Paul O'Donoghue and Goran Bunjevcevic.
Defendi's sending off then changed the course of the game but apart from Filipe Morais striking the woodwork with the free-kick from the Defendi foul, they created very little with the man advantage.
We lined-up with Radek Cerny returning in goal as Clive Allen opted for O'Donoghue and Defendi in central defence with Bunjevcevic and Davis providing the experience in the centre of the park.
The first effort of note came after 10 minutes when Oliveira latched onto the loose ball 30 yards and launched into a drive that sailed over. It had been scrappy up to then and continued that way although we looked to play the more controlled football.
Davis looked a class act early on and soon found his passing range but it was a Defendi 60-yarder that led to our first chance, his pass controlled well by Limbersky who then played in Yeates, his cut back was cut out with Malcolm waiting.
Chelsea almost caught us out after 22 minutes when Filipe Morais took a quick free-kick that Woodards headed over from 12 yards.
Davis was involved again in our best chance to date, leaving Hollands on the floor before spreading play wide to Limbersky. It was the same combination that opened Chelsea up a little earlier as Limbersky rolled the ball into Yeates only for Nuno Morais to block his shot.
A quick free-kick caused some panic after 37 minutes as Malcolm won the header and Defendi went in for the second ball but his toe-poked effort was deflected wide. Chances remained at a premium although Cerny needed to be off his line sharply to gather as Hollands threatened to break clear and Malcolm was inches away from Ifil's cross just before the break.
We upped the pace at the start of the second half and Yeates forced the first serious save of the game after 48 minutes as Pidgeley tipped his low shot to the near post around for a corner.
Pidgeley was there again five minutes later to deny us with a double save, palming out O'Donoghue's downward header before getting up quickly to block Bunjevcevic's follow up. The keeper then made a more routine stop to his right after Yeates was teed up by Malcolm.
Bunjevcevic fired wide before the key moment on the hour. Joe Tillen was sent through on goal only for Defendi to check his run with the most minor of touches just outside the box. Nevertheless, referee Mr Vaughan showed a straight red card and Defendi was off.
Thankfully, the free-kick didn't lead to a goal but it couldn't have been closer as Filipe Morais' curler from 20 yards struck the woodwork with Cerny beaten.
Jamie O'Hara and Kieranb McKenna entered the fray after 65 minutes as Chelsea started to see more of the ball with the man advantage. Oliveira set up a chance for Tillen after cutting between McKenna and McKie but Tillen failed to hit the target and Filipe Morais blazed over well placed.
David Limbersky's pace almost caught Chelsea out after 75 minutes as he streaked away from Smith and Grant and crossed low for Yeates but he was crowded out.
Steven Watt had the next chance after 83 minutes, a powerful header from Hollands' corner that went straight at Cerny and play switched straight up the other end as Bunjevcevic climbed high to beat Pidgeley to Yeates' free-kick but his header went wide.
As it turned out, the final chance of the match fell to us as O'Hara swung in a deep free-kick with seconds left that McKenna was inches away from a tap in at the far post.
48mins: First serious save of the night as Yeates broke down the right and his near post shot was tipped wide by Pidgeley.
53mins: SAVES. Pidgeley did well to keep out O'Donoghue's downward header from Yeates' corner and even better to get up and block Bunjevcevic's follow up from close range.
60mins: RED CARD. Tillen through on goal, Defendi checked his run on the edge of the area with the slightest of touches but sent off.
61mins: WOODWORK. Filipe Morais curled the resulting free-kick onto the right upright with Cerny beaten.
66mins: Tillen decent shooting chance after Oliveira beat two tackles down our left but failed to hit target.
Injury time: CLOSE. McKenna inches away from converting O'Hara's deep free-kick.
Chelsea: Pidgeley, Smith, Tillen, N Morais, Watt, Grant, Oliveira, F Morais (Younghusband, 79), Woodards, Hollands, Tillen (Simmonds, 90). Subs: Russell, Hudell, Mancienne.
Spurs: Cerny, Ifil, McKie, Bunjevcevic, Defendi, O'Donoghue, Dilevski, Davis (McKenna, 65), Yeates, Malcolm (O'Hara, 65), Limbersky. Subs: Eyre, Kyriacou, Hallfredsson.
Our reserves held on for a deserved draw against Chelsea at Aldershot on Monday night after playing the final 30 minutes with 10 men following Rodrigo Defendi's sending off.